[musingsole]

The Method Resolution Order (MRO) is firm and documented. It's just not something anyone keeps in mind unless you use multiple inheritance a lot.

Conflicts are determined by the MRO. If some classes don't call super(), then they won't call super --> classes further down the MRO won't be called and won't be initialized.

The choice isn't: multiple inheritance or a couple lines. In the right situation, multiple inheritance could save hundreds of lines and condense a complicated mechanism into a simplistic one. Used flippantly, they can be a nightmare -- but that's true of all programming paradigms.