still even wikipedia confirms that millions of gauls were either killed or enslaved, so your saying that genocide is not possible in the antiquity is somewhat dubious.
Wikipedia is precising these numbers are from Caesar. So I fail to see how "my" saying (that is actually less MY personal opinion than academic one, as far it's grieves my ego) is really put in question there.
First, laeti as serves?The Frisii (germanic tribe) was forced to settle within the roman empire as serfs. "Among them were the Frisii and Chamvi, who were described in the Panegyrici Latini Manuscript VIII) as being forced to resettle within Roman territory as laeti(i.e., Roman-era serfs) in c. 296."
I don't know who's the translator but I've rarely seen something this badly put. Or it's incompetence, or it's hilariously biased.
Laeti is, basically, a non-roman communauty that, after a defeat, is indeed moved into a province or a region to farm and work AND to serve as recruitment into the army.
It's somewhat between the colonate and the federation.
The big difference is that colons didn't served in the army and their children couldn't acceed to citizenship (it's debated if the Caracalla Edict granted them citizenship. Probably was done case by case)
Second, the people reduced to laetus situation were raiders and not natives. The plan was to move a neighboring raiding part of the tribe out of the borders and to control it directly under the emperor's rule.
But, while it could be infamous (particularly the impossibility of using weapons, while it was key to social indentity) the status of laeti within the roman army could be valorisationg (we don't count the Frankish - Salian - that benefited from it to became officers or even military elites).
Servage doesn't exist in Western Europe before...well, let's say VI century. You'll need first an agricultural crisis (OTL it was both less agricultural results due to climatic changes and less profits avaible in the same time, furthermore the decentralisation of production, due to the lesser profit avaible in great demesnes, helped largely).i think, my POD about resettling some italians as serfs in the daco-slavic empire is doable, possible when in the right circumstances.
And, again, expecting at best 250 000 Dacians to move 500 000 Romans is not only anachronic, but absurd as well.