Well, for one it would depend on how well implemented it was.
Look at the n^2 versions of ranger there are - even with spells in the mix it is hard to get the balance right.
That aside - what could this class has that (1) is not magic, and (2) can compete with foresight, force cage, dimension door/teleport, simulacrum, greater invisibility, banishment etcetera? These all have very strong combat and out of combat uses (well, no combat uses for teleport, but plenty for dimension door).
124 vs 192 hp at level 15 with a 14 con for either. The gap isn't that wide at all, unless the fighter is also stacking con more than the wizard; the reverse is probably more likely.
However if the adventuring day is short (as many are) this isn't much of an issue because the wizard doesn't come close to running out of resources.