hmmmmm
Sascha is a popular boys name where I live, or at least it was popular in the 80s, so it seems dated. All the Saschas I know are actually named
Sascha, not
Alexander.
Even though I grew up with several boys named
Sascha I always preferred it on a girl (spelled
Sasha), it just seems very feminine to me. I also prefer it on its own and don't really like it as just a nickname for
Aleksandr or
Aleksandra. You could compare it to
Natasha or
Sonia, both Russian nicknames but they aren't nicknamey at all so I would rather use them on their own and not as nicknames for
Natalia and
Sofia.
I also think that
Sasha will become quite popular for girls.
So yeah. I don't like it on a boy but I like it on a girl and it isn't nicknamey to me so I really prefer it on its own. I mean
Sasha isn't short or cutesy like
Alfie or
Tim so it works fine on its own and if you never call him
Alexander anyway, why name him
Alexander ?