If some of the targets of Captain America's first ability become illegal, the original division of damage still applies, but the damage that would have been dealt to illegal targets isn't dealt at all
That's all changed in recent years, however
Aside from a few cards here and there, the main difference between competitive Pioneer and competitive Explorer is that you cant play the Lotus Field combo deck in Explorer
Not only can he tutor up Equipment from your deck, but hes got a nifty trigger-doubling ability, too
Creatures (6) Planeswalkers (6) Lands (19) Spells (29) 3 Oblivion Stone 4 Sylvan Scrying 4 Chromatic Sphere 4 Chromatic Star 2 Relic of Progenitus 4 Expedition Map 4 Ancient Stirrings 4 Collective Brutality Sideboard This version is very similar to the other Green Tron lists, but instead of using red or white, Twibs chose to play black
Control decks want to be able to slow down the game by handling early aggressive plays that might do critical damage prior to mass removal, they want to be able to do multiple things in a turn and they want to be able to snipe out tenacious creatures that might survive a mass removal spell