People should probably be allowed to use their real name, even if it coincides with a historical figure. I personally know a César, and although it's not so common for Spanish names to include two given names (outside a handful of specific common pairs), I wouldn't be surprised if there are living people whose parents named them Julio César. More contemporaneously, there are plenty of living people (particularly from Latin America) named Lenin.

Peter Taylor‭ I think moderators should be able to use common sense here, just as we expect users to pick user names using common sense. If I was a user and my name was Lenin, I would surely be aware of the historical figure and pick a more explicit name, Julio Lenin or whatever applies. Also I suspect that the accent aigu might be present? That is, Lénin, or...?

Lenín, so potentially overlookable.

Peter Taylor‭ Either way, I think such users can get a friendly nudge to pick another user name. On less tolerant platforms such names might just get outright rejected/banned. But then of course almost everything means something bad in some other language or context, so it has to be within reason.

It is the same origin, but the spelling is different in English for the first example: Julius Caesar. And there is also the acute accent difference. Shouldn't that be enough to disambiguate?