Changing the world, one levelling rule at a time?

Hey so here's a crazy thought:

Let's make owned levels account for the party, the way seen levels typically are shared.  In other words, every Pokemon owned by the party helps them all level up.

Beneficial repercussions:
1. Capture Specialists are no longer a 'selfish' class.  They suddenly go from existing to increase their own level (so they can increase their own level further), to existing to increase EVERYONE'S level.  This single change immediately fixes an issue with an entire set of classes.
2. Along this vein, everyone in the party is now encouraged to contribute.
3. It also gets rid of some of the level inequality issues that lots of voices seem to prefer to avoid.

Non-beneficial:
1. I guess if you like the inequality this would be bad?
2. This WOULD require some numbers retweaking.  Kuji has said he's actually doing this for his party in a game, with 20 owned being the "Magic number" per level, and it's working very well for him.  More importantly, Collector will probably need some reevaluating so it doesn't become Infinite Levels and completely overwhelm the rest of the options.

So... yeah.  Thoughts?