#3 Sign Brock Lesnar
Brock Lesnar is currently affiliated with WWE as the Universal champion on RAW but his contract with WWE differs from other Superstars.
At present, he is simultaneously signed with WWE and UFC on a per appearance basis, allowing him to be free to choose which company he wants to work for and when.
I'm not fully aware of the details in Lesnar's contract so I won't predict that he would make an appearance for AEW's events and press conferences but by the time AEW starts airing on TV, WWE would have run out of his current contract and the no. of appearances Lesnar is bound to make.
Money is the only motivation left for Lesnar to come back to the squared circle time and again, and Tony Khan spearheading the monetary department, it isn't impossible to see Lesnar in AEW.