At 7 weeks the cockerel may be in charge.... or not.
Way too young for hormones to be playing much of a role...the most assertive/aggressive chick could also be a pullet.
FYI.....semantics, maybe, but can be important communication terms when discussing chicken behavior.
Female chickens are...
Ditto Dat^^^
Try putting them all together, if that doesn't go well, try putting 1 or 2 of one group in with the other group...chicken juggling!
Keep mixing and matching until they are as harmonious as possible.
It's all about territory and resources(space/food/water).
Existing birds will...