4 teams is 24*7/4 = 42 hrs/wk
5 teams is 24*7/5 = 33.6 hrs/wk
6 teasm is 24*7/6 = 28 hrs week
and the shift length 8hrs or 12 hrs or some hybrid system.
The EWTD directive limits the working week (with exceptions) to 48hrs
averaged over a rolling 17 week period and guarantees 11hrs unbroken rest
every day.
So as you may gather from the information you have provided it's diffiocult
to provide too much guidance.