There are many ways to handle a processional. Which one you choose will depend on other elements of your ceremony.
List on the paper
There are three solutions, all of which are equally correct. If your page is wide enough, you can list both of them on the same line.
On a narrow page, list them in the order that they enter. Or, if they enter together, list them alphabetically.
Must the groom have two best men?
No. The groom doesn't even have to come up with the same total number of attendants as the bride. It's not that difficult to arrange "uneven" wedding parties so they look good.
If there is an even total number of male and female adult attendants, each maid of honor exits with a male escort. The maid of honor who stands nearest you is escorted by the best man if there's only one best man.
If there are more female attendants, both maids of honor are escorted by the best man.