Little late to this party but I will do whatever I can to find a way to make castform work. I loved rotom enough to play it from release to rotation. The stadium vs tool issue is not a small one (extra tools could all at least give free retreat, increased damage, or confusion, etc., whereas only one stadium can be used at a time (and the fire attacker, being the only one with decent output, discards a stadium so it can't really be a defensive one) . Not to mention hapu and clay and 2 stadiums that could have deleted other stadiums (viridian and hearth) will soon rotate so non-research ways of deleting stadiums are going to have to be things like Cinncino or galarian meowth, or bad supporters like Milo, Allister, Bea?!, Oleana!?!
But maybe new cards will be printed that make this worthwhile, or new stadiums that say discard up to 3 stadiums directly from your deck, if you do, search your deck for 3 more stadiums and put them in your hand... or something...