I think
Tobias and
Veronica would make a great sibset. I too really like the name
Tobias but hate the nn
Toby. I don't think it'd be too hard to prevent the
Toby nn in environments where you have more control but in environments where you have less control, like what his school friends call him,
Tobias may decide on his own that he prefers
Toby. I've known two Tobiases (Tobiai? Tobii?) and both went by
Toby. I think the nn issue is the same with
Veronica. I know two Veronicas. One is
Ronnie. The other is just
Veronica and has never gone by any nn. So I think it's plausible for
Veronica to not have a nn.