Zardnaar
Legend
I think Wisdom proficiency is a lot more valuable than Constitution or Dexterity. This is especially true since a Bladesinger is probably dumping Wisdom (unless you are mutliclassing to Ranger).
I realize that Constitution is what is used for concentration checks, but those are usually easy saves, if you are concentrating you are probably not getting hit a lot anyhow and with Bladesong and Warcaster you have bonuses to those.
A failed wisdom save on the other hand will often incapacitate you and make you lose concentration anyway.
Paladin is a really hard multiclass for a Bladesinger. On point buy you need to dump Constitution to do this effectively. There are builds out there - a Half Orc or Dwarf with Tough Feat comes to mind.
Pakadin dips rough. Also be tempted by that second level for smites.