Non-caster multiclassing was never a problem IME.
Eh. If you don't use fractional BABs and saves, the numbers can get really wonky at times. And there are a fair number of base classes that seem to live (at least in 3.5) as 1-3 level dip classes.
Casters were the major problem with 3.x multiclassing, but non-casters were scarcely perfect.