I have the same problem with my females.
If the lower ranking female dog comes
up to me for attention, the Alpha female gets all bent out of shape.
I always try make shure I pet the Alpha female first.
IF the highter ranking dog is still
getting bent out of shape, I will
repremand her to let her know
that as King I can pet whomever I please.
This works for me.
If your dogs are not food aggressive you
might try a reward system.
Rewarding them when they do something good and ignoring them when they don't.
Good luck, after 3 years my top female
still puts the lower rank in her place
when I am around.