The problem with Untamed is that it becomes expensive when you lvl up in leagues you play. When I switched from silver to gold, I threw away most of my UT cards with low lvl to avoid being punished for missing lvl cards. And cheap CL cards invite you to move to higher leagues as long as the CL is in print.
As for the RW summoners, I wanted to have them all, too :) But after closer look, I gave up on Aquatus and Dallan. Both are so so, imho.
Ilthain is great, I use him very often. You can easily cover 2 and sometimes 3 sources of dmg and backfire it to opponent.
Same with Owster from Dice. Especially when Obsidian is played so often.
And with Amplify opposite team often kill themselves.