Hi stoogeska48. My advice would be to treat them as equals. Be a benevolent leader and patient instructor to them both. Do not use praise and treats to encourage any aggressive, assertive behaviorin either of them. If one dog is being pushy or bossy, treat and praise the OTHER dog. Withyour guidance and management they can be excellent friends or...at the very least...coexist together without fighting. Dogs are very fluid in their packs. There aren't leaders, per se and size does not matter. Temperament does. A dog that can get away with the best spot or eating all the food, will. but not because it is the leader. It will simply because it CAN. In my opinion, dominance theory has been thouroughly debunked. Check out some of the stickies at the tops of the sub-forums here and read some of the new ideas that are out there. I dare say, they may make more sense to you. I especially enjoy the non linear dog (website) and beyond ceasar Milan (another site) with "the 100 silliest things people say about dogs" by Alexandra Semianova (I may have spelled her name wrong).
The "science" (and I use quotes here because the theories and studies as so very flawed) used to spread the idea that dogs operate on a dominant hierarchy was based on one man's short study of captive wolves...Schenkel was his name i think....and even HE has said the study was flawed and never should have been transferred to domestic dog behavior in the first place. Dog's (and wolves for that matter) live in families. Yes, dogs will correct undesirable behavior and have disputes but never with too much force or one dog always taking over. they live as a fluid unit, coming and going as they please, sleeping, eating, learning, teaching and travelling together and not with one dog always in the lead, taking cahrge, disciplining or eating first or getting the best or highest nap spot. They are highly social animals that tolerate their own and other species as part of their pack with great alacrity but when they live with humans, we tend to put all these erroneous ideas of alpha dog upon them when what we should be doing is treating them like students. Teach them how they should behave in your home, and if you are consistent and kind about it then you will have a model canine citizen.
I call it the Mary Poppins approach. Kind but firm.

good luck