Would be awesome to add grove of the burnwillows and punishing fire (and kavu predator), but groves are expensive.

Shivan wurm may be a better choice than two-headed dragon. Bouncing your blastoderm is a bonus here.  But who knows?  Pros disagreed, so either should be fine.  (we'll go with ancient hydra because it's easier to acquire - although I have a feeling it was only a pro-caliber card because it used to abuse stacked combat damage.  It probably sucks a lot now.  Oh well.)  You could try Gleancrawler instead.  Or maybe vorstclaw or changeling titan.

For casual play, the idols can be replaced with any easy to cast, efficient three-drop.  Lavacore elemental could work here, and centaur courser would be fine.

concordant crossroads horned kavu