Should I rank up champs I can potentially pull as 7 stars

I'm at high level paragon almost valiant and currently own 30 rank 1s, 5 rank 2s and 1 rank 3. I've completely stopped ranking 6 stars in fear of pulling them as 7 stars. What should I do. Rank up my 6 star juggs or only rank up 6 star locked like kitty
0
Comments
You never know when you will pull a 7* juggernaut
I pulled him once and I never got to dupe him
Juggs
Serpent
Onslaught
It’s not too terrible if you don’t mind bringing double of a champ.