I don't think that Pallegina will be able to multi class, unlike Eder/Serafen, etc. We're talking speculatively, right?
In any case, I think multi class paladins and fighters will have difficulties tanking as well as single class fighters & paladins because of the hit to their power level. It's my impression that it's a trade off between versatility (multi) and the power to do one thing really well (single class).