If you look at Gen 3 none of the big companies had more than one GG, YG - Blackpink, JYP - Twice, SM - Red Velvet and looking around generally only really CUBE had a couple on the go with CLC and G-IDLE.
Now it looks like maybe the market has expanded to the point you can go for more than one:
YG : Blackpink and YGNGG arriving
SM : Red Velvet and AESPA
PlayM : Apink and Weekly
CUBE : G-IDLE, Lightsum, CLC (although sadly the latter will probably disband)