For sure it's okay. As long as you're being proactive. Which you most certainly werein that zac game.
My cs as naut jg is cringe worthy 99% of the time. However an average score would be 1/2/8 with eh cs.
It's not about how often you cs, but how you utilize your time when you aren't.
If you have eh cs and score average of 0/2/1 then perhaps your decision making and time management need some work.
Can give some insight for zac as he's one of mah baes. (Might improve ur cs while maintaining ur pressure)
Do ur 3 camps blue buff side and look to gank.
If it fails/you don't gank get scuttle crab and check again for gank opportunities. Generally the 2 closest lanes (if one doesn't work, try the other)
After gank/scuttle do ur red side (only do krugs if ur already heading top/bot respectively), get scuttle and check for more ganks.
Rinse and repeat dude
As long as you apply succcessful pressure (you make em use summoners or kill em) you're doing great.