Sure we could probably put Loxodon and Behemoth in there, but we only have 300 cards. It's a hefty limitation. If we weren't limited, I'd put both in there. With the upper limit I think it's more important to keep a good toolbox going.

Are there other equipments we've overlooked?

I think I slightly prefer Acidic Slime just because I can recur or what not and still get the ability. I don't know if planeswalkers are prevalent enough to make Mold Shambler the wiser choice. I suppose it's one or the other and then change it later if needed.