Legendary Character Drop

I have managed to obtain all Customization for Zombies and Plants (not Infinity Time Items). And I'm still ranking up characters and getting the upgrades to fill my book collection. But the issue here is that it takes an eternity to obtain an Character Piece for Computer Scientist, Disco Chomper, Toxic Brainz and Iron Citron, which are obtained from my "knowledge" from 15k, and the other 35k packs. Through the past weeks I've been only getting Consumables over and over and over again, no luck in getting these amazing Legendary's (including hats). I just thought for the me and the community that Legendary's shouldn't be hard to obtain from packs since Legendary's aren't "Overpowered". I just thought I'd share my thought on the issue since you guys are already adding new characters and I still haven't gotten a Piece for one yet. Thanks!