The hostility would likely predate modern government tracking systems and bueracracies. While going from Jimmy Brown to Jim Brown wouldn't raise much of an eyeb

The hostility would likely predate modern government tracking systems and bueracracies. While going from Jimmy Brown to Jim Brown wouldn't raise much of an eyebrow (head of your household now - fair enough) but going by a different name in every town would raise suspicion of being a spy, serial con artist, fugitive, or other sort of scoundrel. Bypassing "means of trust" like word about you gets viewed with suspicion even without rationalization of rules imposed by might maked right. Name changes seem to not have been frowned upon generally if they had significance. Often they were recorded as part of a rise of status whether formally like say becoming pope or a Norse deed name style like being known as Shieldbreaker because you struck the blow that split a foe's shield in two. As for tracking - many buggy but functional systems linger at good enough for generations with a weirdly stable whole. Even if you can get a "NULL" vanity plate you shouldn't unless you like taking the chance of receiving every ticket for cars without plates and having to dig your way out of that mess.