I actually cut them
because of how much they encourage durdly midrange decks (already prevalent with my group).
I've opted for a different suite at this point which pushes guys towards one end of the spectrum or the other. Thrun for example you really want to start beating down with because once bigger stuff comes out he's not doing much for you without equipment or some kind of evasion.
Surrak, the Hunt Caller helps push guys aggressive (really liking this dude), as does
Mwonvuli Acid-Moss (which is stellar on turn 3 and progressively less good as the game goes on).
Natural order for "sac-an-elf-into-something-nasty" combo plan. I think those are my only must-run green 4's at this point.
For a less slow version of the Master/Polukranos fight mechanic, you can try
Foe-Razer Regent. I have little testing results on this guy, but I think he might actually be a solid fight-on-a-stick dude. Finally. He's 7 mana, but if you are heavy green that's like 6 (or even 5). Also a natural order target.