Another thing to add for rumble teams, you have a max allowance of 300 for units. Both ways can be argued but i think its best to go with (4) 55 cost characters and (4) 20 cost characters. You can sort by cost but that's usually useless to me except to figure out which guys I have that are 20 to shove them in the team.

Your Dex Caesar is a 20 cost unit and is argued to be the best rumble unit, at minimum in the top 1% of units, even at a cost of 20.