Being a bit more specific, lets take a gander at the common core of good modular creatures, the ones that dont feel like an absolute waste of a slot to play on account of being a 1/1 for 1
Thats just one more in the long list of reasons this is a horrible, doomed idea.
Then the mono-Blue flying seven-drop will also drop their cost by two as well, but this time from anywhere that isn't our hand and it's got foretell for five
Elves are the best at going wide with tokens, ramping substantially, and pumping each other up as other elves enter (looking at you, Marwyn, the Nurturer)
The Alchemy version, Thayan Evokers, ditches most of this design altogether for something entirely different, though double team does a fine myriad impression