Unless it has haste, of course
Though you could easily build a Commander deck around either Relentless Rats or Rat Colony
I think the one thing I would've liked to see more of in the list are summon cards: if you look at our commander options, Tidus, Yuna's Guardian and Yuna, Grand Summoner, both clearly work exceptionally well with the new summon creatures like Summon: Valefor as Tidus can remove lore counters to keep them around longer and Yuna can pump up creatures when the summons die, and that's a unique new game design space that would differentiate the deck from more generic +1/+1 Counter lists out there
This Character card is another alternate art variant
Assuming you've built your deck around the creature type, you usually won't have problems putting at least a few cards into play for free
So often do people greedily play the powerful card over the humble Chromatic Shape and never see their error as the heroic work of the Chromatic Shapes is so hard to even notice