First, don't feel the need to "even it out". It is actually very common these days to have uneven wedding parties. If you really need it to be symmetrical for pictures or what not, it is fine, but not necessary at all. I had
two guys and three girls on my side; he had four guys. I feel like it was just fine.

As far as processionals go, I have never walked with anyone in any wedding I have been in. Either all the guys have walked out with the groom at once, or they have gone down individually before the BM and MOH. That way, the BM get
all the fun of their walk with the bouquet in all its shining glory.
If you mean the recessional at the end, don't worry too much about this as well.
I had each girl walk out with two guys on their arms. I have walked down with other girls, two girls with one guy, two guys, and alone at the end
of ceremonies. Have the people up there that are meaningful to you and just make the rest happen how it needs to. Keep in mind, all attention will be on you. As long as you have something planned and organized, no one will notice!