If you pair up Antman, Squirrel then Cap after them and then place Onslaught last you've guaranteed yourself a spot.
Then where the squirrels are placed, place down Hawkeye then Korg or Nightcrawler then lastly place Kazar u should have your 2nd spot on the board secured, this is not 100% as u may not draw the cards in the right order or the boards locations may screw you up so learn how to play around it with these combos.
The rest of the characters you don't use could be slight replacements for other cards or could be used as sacrifices to increase your chance at winning or they can be used as fillers for unused spots.
The Only Counter to this deck is if the enemy has Iron Man or Odin and they play their cards right or if the locations are power based at starting rounds.
Hope this helps, Enjoy :)