Yeah, there is more than winning at stake(which does not excuse bad game design but eh), its more placing each character where they can make an impact on the scenario. This is problematic with party based games, where a default assumption is the whole party moves as one unit, and with combat based games, where the default conflict is martial in nature(and thus, the best way of killing things and not being killed, in that order, wins).
What you need to deal with power and focus discrepancy is breaking the one cardinal rule of GMing, Don't Split The Party. Divide them up by role and strengths, and place appropriate conflict therein. The problem again with that, is when you have multiple characters specialized in the same field, and a power gap is highly apparent.
White Wolf games do it slightly better in that regard. The starting premise of their supernatural lines are basically 'ok you're a Jedi, what sort?', so everyone is on the same starting supernatural footing. The 'expected' party(in quotes because few people actually run it straight like that), would have one character of each specialty archetype: Bruiser, Diplomat, Handyman(lore, tools, etc), Sneak and Special, and due to the basic game mechanic, competence gap grows slowly.
The problem of course, arises when you have games where one type of challenge becomes more common, most often in Bruising and Diplomacy, where you can have entire sessions based on them. Some fields are just harder to provide for than others.