I can only speak for myself, but I think many of us would love to have a look at your lineup if it helps you.
There may be different advices and you can takes the best one for your needs.
I’m so long in dominator now that I almost forgot how it was at the time when it was hard for me to reach it.
I’ve got more than 25 lvl 40 VIPs by now. My lineup in dominator is always meat shield, lvl 40 VIP and some middle class dino for the rest. Lvl 40 VIPs have a cooldown of one day (more or less), so that I could make 25 fights per day which I almost always win.
I suppose this has not much to do with your current lineup, but I would of course take a look at your dinos and give you my opinion.