Serbian names in a Walloon land

The southern edge of our Romania was, aforetimes, the Wallachia. The first links the land to a language; the latter, to a people. The people were Romanised Celts: walloons, as the Belgians call them.

This implies that Wallachia was a throughly Dacian and/or Latin land as far as local records take it. So it interested me a couple weeks back when Old European Culture found Yugo-Slavic toponyms here.

I am on record as seeing much of our Serbia as ancestrally Albanian. However as I reread that post, it concentrated on the Ibër. Wallachia lies to the east of that, along the Byzantine Danube.

I'll start with a philology of "Wallachia". Other cognates are "Welsh" and "Wallace". The basal word is German. The Goths ruled the region up to the AD 500s or so but the Avars and Slavs kicked 'em out, so I don't see this exonym sticking. The Vikings and Old English(!) got to the Crimea but I don't think they settled the Danube. In the late Middle Ages, plenty of German-speaking lords settled across that old Habsburg transylvania. The Wallacians had already separated from the Kingdom of Hungary and, when the Habsburgs had Hungary, those lands stayed just out of their reach - until the Great War debacle. So I see "Wallachia" as a Habsburg imposition.

As I dig up the primary sources, Wiki offers this in AD 1485: Haec Inscriptio ex Valachico in Latinam versa est sed Rex Ruthenica Lingua scriptam accepta. It's a (Slavic) Pole saying it, but his world is increasingly Central European - hence the Latin - which explains his recourse to a German exonym. Here is a local "Wallachic" language, not "Ruthene" =Slavic. In 1534, one Tranquillo Andronico notes the Wallaces as speaking Romance. Scholars agree that this people did not switch from, say, Celtic in those fifty years; that they were in 1485 already walloons speaking a form of our Romanian.

Adding to the mix, Romanian has a sister: Aromanian, sometimes "Vlach". (Wallaces again!) Aromanian clusters along Greece's northern border, both sides, mostly west. Where Romanian (and Moglen) took on Slavic, Aromanian took on Greek. The split is vaguely dated: AD 800-1200. I know not if Aromanian shares in the Balkan Sprachbund with Albanian, Romanian, and Yugoslav - I assume, yes. Given Aromanian's Greek loans, implicitly late Greek; I see Basil II's hand in this.

Before anyone answers what all this Yugoslav is doing in Wallachian toponyms, I'd first answer: to what degree is Aromanian a Balkan language, and how did it attract its Sprachbund elements; and, what's the history of Greek loanwords into Aromanian? I also want to know when and why this German term "Vlach" got applied to Aromanians far from Habsburg influence, deep in the Ottoman Europe.