The term Bridezilla is used so much that we often forget that there are sometimes overbearing grooms-to-be as well! Although I have not had a lot of experience with these Groomzillas, my contact with them has been quite enough to last me a lifetime!
These men are very hands on which I welcome, but when they're participation is marked chaos, conflict, and discord- there is a problem. I often find myself trying to be the mediator between the bride , groom, and bride's parents (who are footing the bill). Not an easy task to say the least.
One of the easiest ways to help alleviate a groomzilla situation is to let the groom know that his opinion does count. After all, it is his special day as well. Do not discount the efforts that he is trying to make to contribute to making the wedding memorable for all.
Also, compromise. This is the beginning of what will be a lifetime of compromises to be made. Being selfish is not going to help the situation, but only increase the roar in this groom-to-be. We want to simmer the fire, not reignite it!
The last tip is to just remember why you are marrying each other in the first place. The love that you share for one another is reason for this joyous occasion. Your groomzilla loves you with all his heart and wants your special day to express that! Give him the opportunity to express his love in his special way/style (within reason, lol)!