I would like it to work one of two ways.
Either let creatures with proper types count for more than one
OR
Let more than just the 4 Trope Classes work with it so that your could use party in a (non 5 Color Human lul) deck not fully dedicated to that very thing mechanic.
They've already said you'll only need at minimum 2 colors to get a full party. Heck Wizard and warrior are the 2 most common creature classes in the game. Cleric has 418 possible selections (W: 270, U: 14, B: 65, R: 7, G: 15 - only checked pure colors, skipped multi) while Rogue is the thinnest with 248 (W: 3, U: 81, B: 91, R: 56, G: 15). And that's just with the current list and a few of the releases. Given anything not beast in Zendi3 seems to have one of the 4 classes on it, all those numbers look to increase.
With no trample, or haste in a multiplayer game, which also requires you to have another creature on the field through resolution in a multiplayer game.
Oh man, if only lightning greaves existed. Whatever shall we do?
Kay, I've seen much worse in commander, also requiring that changling to stick on the field in a multiplayer game.
I am not really..afraid of either of those. Sure I might get got by the 200/200 creature.
Sometimes you get got by bad shit, that is why I have my Rule of 3 "Proper" Planeswalkers in my EDH decks..because once in a while they get people.
Yeah, people are going to invest so much to take out your Universal automaton. Oh wait, you don't even have to. Just cast Shields of velis vel on whatever you got on the field and then your party plans can go off.
Of course, changeling is also in a little format called
modern but sure, we can break that format some more - no problem.
As for party, just seems like a waste of a mechanic what was actually wrong with ally? shoehorning every card into one of 4 creature types seems pretty stifling.
Mark admitted in his state of design that they're not happy the sets don't have much cross play. "Ally" is incredibly parasitic, "locking" those creatures into zendikar 3 only decks. At least this design of party allows you to pull more cards from outside the set into your party deck for fun.
i.e.