I have no clue which wave is which but I've seen 3 waves hit since September:
1. The wave with Skaar, Scarlet Spider, Dr. Doom, etc. and I think Strange was in that one too
2. The wave with Steve Rodgers, X-23, Ultron, etc.
3. The wave with Ultimate Magneto, Astonishing Wolverine, Iceman, etc. This was the latest wave I've found