One piece of good news for you: Riverjumper counts herself! Even on an empty board, she's a 2/4 with Ward. Auto-include.

Pyramid Warden is definitely interesting. If you can get it in the mulligan it seems big, and as you say, giving back some 1-2 mana creatures isn't too bad. Especially if you've got Canopy Sniper to mow them down a second time.

The biggest thing you opened my eyes to is Steadfast Scout. That's a steep requirement when I could just play Hunt Warden. Good call.