That's exactly what I was alluding to.
Like the ideal time to introduce Cooler would've been at any time after Trunks killed Frieza and King Cold. So when he shows up you could easily throw in some flashback of Cooler mocking his dead/cyborg brother as their dad had him put back together and make some remark about how he aint helping him and he has his own plans in (insert region).
Now after Frieza is back a second time and Goku can sense high power levels all over the universe and ****, knows of the South, East, and West kais cant just say Cooler was over here ****ing **** up unchecked.
Probably gonna have to throw fam in the Dead Zone and then let him out now to explain his absence
This could work but he'd less of a villain with that approach.
The stakes really haven't been there with Super. Eventually like I've said before I want someone to come through killing and it be permanent. They rely to heavily on all the different versions of the dragon balls.