I suggest that Arachosia < Haraxvaitī- < सरस्वती (R̥gveda) is the Sarasvati Vedic River Basin, Meluhha speakers moved westwards to Drangiana which is Śakasthāna. Both the regions constituted the region of Meluhha speakers of Sarasvati Civilization, from ca. 8th millennium BCE and constituted the underlying speech for mlecchita vikalpa (Meluhha Indus Script cipher). The migrations of people from Kurukshetra (Sarasvati Basin) isattested in Baudhāyana Śrautasūtra.
The presence of Meluhha settlements in Ancient Near East is attested in cuneiform texts. this finds confirmation in an ancient text.
Sealed failaka jar and 14 Ancient Near East artifacts (including seals) with Indus Script hieroglyphs signify iron (metal) smelting work of Bronze Age http://tinyurl.com/h4ynklt
Periplus maris Erythaei, 37, 39, 49 refers to sailors bring bdellium from Gedrosia and India. (cf. Lassen, Indische Alterthumskunde, I, 289 f. 530,iii,43 Ta. akil (in cpds. akiṛ-) eagle-wood, Aquilaria agallocha; the drug agar obtained from the tree; akku eagle-wood. Ma. akil aloe wood, A. agallocha. Ka. agil the balsam tree which yields bdellium, Amyris agallocha; the dark species of Agallochum; fragrance. Tu. agilů a kind of tree; kari agilů Agallochum. / Cf. Skt. aguru-, agaru-; Pali akalu, akaḷu, agaru, agalu, agaḷu; Turner, CDIAL, no. 49. (DEDR 13) agaru m.n. ʻ fragrant Aloe -- tree and wood, Aquilaria agallocha ʼ lex., aguru -- R. [← Drav. Mayrhofer EWA i 17 with lit.] Pa. agalu -- , aggalu -- m., akalu -- m. ʻ a partic. ointment ʼ; Pk. agaru -- , agaluya -- , agaru(a) -- m.n. ʻ Aloe -- tree and wood ʼ; K. agara -- kāth ʻ sandal -- wood ʼ; S. agaru m. ʻ aloe ʼ, P. N. agar m., A. B. agaru, Or. agarū, H. agar, agur m.; G. agar, agru n. ʻ aloe or sandal -- wood ʼ; M. agar m.n. ʻ aloe ʼ, Si. ayal (agil ← Tam. akil).. (CDIAL 49)
सरस्वती [p= 1182,3] N. of a river (celebrated in RV. and held to be a goddess whose identity is much disputed ; most authorities hold that the name सरस्वती is identical with the Avestan Haraquaiti river in Afghanistan , but that it usually means the Indus in the RV. , and only occasionally the small sacred rivers in मध्य-देश [see below] ; the river-goddess has seven sisters and is herself sevenfold , she is called the mother of streams , the best of mothers , of rivers , and of goddesses ; the ऋषिs always recognize the connection of the goddess with the river , and invoke her to descend from the sky , to bestow vitality , renown , and riches ; elsewhere she is described as moving along a golden path and as destroying वृत्र &c ; as a goddess she is often connected with other deities e.g. with पूषन् , इन्द्र , the मरुत्s and the अश्विन्s ; in the आप्री hymns she forms a triad with the sacrificial goddesses इडा and भारती ; accord.to a myth told in the VS. xix , 12 , सरस्वती through speech [वाचा] communicated vigour to इन्द्र ; in the ब्राह्मणs she is identified with वाच् , " Speech " , and in later times becomes goddess of eloquence » below) RV. &c (Monier-Williams)
Arachosia bordered Drangiana to the west, Paropamisadae (i.e. Gandahara) to the north, a part of ancient India to the east, and Gedrosia (or Dexendrusi) to the south. Drangiana refer to Śakastana शक--स्थान [p= 1045,3] name of a country (Monier-Williams) Śaka are mentioned in ākhyāna historical narratioves in contests between वसिष्ठ and विश्वामित्र. The शकs are fabled to have been produced by the Cow of वसिष्ठ , from her sweat , for the destruction of विश्वामित्र's army ; in Mn. x , 44; they are mentioned together with the पौण्ड्रकs , ओड्रs , द्रविडs , काम्बोजs , जवनs or यवनs , पारदs , पह्लवs , चीनs , किरातs , दरदs , and खशs , described by Kull. as क्षत्रियs called after the districts in which they reside: according to the VP. iv , 3.They are sometimes regarded as the followers of शक or शालि-वाहन , and are probably to be identified with the Tartars or Indo-Scythians [Lat. Sacae] conquered by विक्रमा*दित्य (AV.Paris3. Mn. MBh. &c). शकm. a kind of animal Pan5car. (v.l. शल) m. a kind of animal Pan5car. (accord. to L. " a camel " or " an ass "). Since śaka is a synonym of śala, śaka era is a synonym for śālivāhana शालि-वाहन.
In a well-documented and logically argued monograph, Vedveer Arya suggest a date for the saka era. "Since the calendar of Saka era was Chaitradi and amanta, the epoch of the Śaka era must have commenced on 19th Feb 583 BCE." http://bharatkalyan97.blogspot.in/…/the-chronology-of-ancie…
"Arachosia" was named after the name of a river that runs through it, in Greek Arachōtós, today known as the Arghandab, a left bank tributary of the Helmand.( Schmitt, Rüdiger (August 10, 2011). "Arachosia". Encyclopædia Iranica.)
Gedrosia (/dʒɪˈdroʊʒə/; Greek: Γεδρωσία) is the Hellenized name of the part of coastal Baluchistan that roughly corresponds to today's Makran.
Jiroft Civilization covered parts of Sistan and Kerman Province (possibly as early as the 3rd millennium BCE)..
(Nimruz, Kandahar) and the Nok Kundi region of Balochistan (western Pakistan).
Gold 'gorytos' (quiver-and-bow-case) with repousse representation of the capture of a city, from the Tomb of Philip second half of 4th century BC, Thessaloniki, Archaeological Museum.
Skunkha, king of the Sakā tigraxaudā ("pointed-cap-wearing Sakae"). Detail of Behistun Inscription.
Sakas were a Scythian tribe which from the 2nd century BC to the 1st century migrated to the Iranian Plateau and India, where they carved a kingdom known as the Indo-Scythian Kingdom. The Scythians (/ˈsɪθi.ən/ or /ˈsɪði.ən/; from Ancient Greek: Σκύθαι), also known as Scyths, Saka, Sakae, Sacae, Sai, Iskuzai, or Askuzai, were a large group of Iranian. Eurasian nomads who were mentioned by nearby literate peoples as inhabiting large areas in the central Eurasian steppes from about the 9th century BC until about the 1st century BC. The Scythian languages belonged to the Eastern branch of the Iranian languages.
Saka migrated into northwest area of India, attested by a contemporary Kharosthi inscription found on the Mathura lion capital belonging to the Saka kingdom of the Indo-Scythians (200 BC – 400 CE) in northern India,.. In the Persian language of contemporary Iran the territory of Drangiana was called Sakastāna, in Armenian as Sakastan, with similar equivalents in Pahlavi, Greek, Sogdian, Syriac, Arabic, and the Middle Persian tongue used in Turfan, Xinjiang, China. (Bailey, H.W. (1996) "Khotanese Saka Literature", in Ehsan Yarshater (ed), The Cambridge History of Iran, Vol III: The Seleucid, Parthian, and Sasanian Periods, Part 2 (reprint edition), Cambridge: Cambridge University Press, pp 1230–1231.)
Sakastan ("the land of the Saka")> Sistan > Saka > Elamite (Sir-ra-an-qa > Old Persian z-r-k (i.e., Zranka) > Sarangian > Zarangian > Drangiana
"DRANGIANA (or Zarangiana), territory around Lake Hāmūn and the Helmand river in modern Sīstān. The name of the country and its inhabitants is first attested as Old Persian z-r-k (i.e., Zranka)in the great Bīsotūn iii inscription of Darius I (col. I l. 16), apparently the original name...in Herodotus’ tribute list (3.93.2) the Sarangians, Sagartians, Thamanaeans, Utians, Mycians (i.e., all the peoples living in the lands extending from the Iranian central desert through Baluchistan to the Persian Gulf), and neighboring islanders were included in the fourteenth tax district, required to pay the relatively high amount of 600 talents annually. " (http://www.iranicaonline.org/articles/drangiana)