Yes, those that are under three CMC are perfectly fine additions to the deck. Anything that is legal for commander (including its ban list) is legal in Tiny leaders (excluding Tl's banlist). Though filtering mana is probably not the best option for Tiny leaders.
June 23, 2015 2:35 a.m.
Thanks for that.
I was only using Opal Palace as an example.
it's actually Command Tower that I'm interested in using.
June 23, 2015 2:49 a.m.
You can play cards in any format they are legal for.
Command Tower can be played in Legacy too, but since you lack a Commander in Legacy, it simply doesn't produce any mana.