Forum adverts like this one are shown to any user who is not logged in. Join us by filling out a tiny 3 field form and you will get your own, free, dakka user account which gives a good range of benefits to you: No adverts like this in the forums anymore. Times and dates in your local timezone. Full tracking of what you have read so you can skip to your first unread post, easily see what has changed since you last logged in, and easily see what is new at a glance. Email notifications for threads you want to watch closely. Being a part of the oldest wargaming community on the net. If you are already a member then feel free to login now.

Pondering our Dominion vs Romulan fleets, would adding in Feds and Klingons, retaining ship purity, dramatically tip the balance against the Dominion or does it's mix of Jem'Hadar, Cardassian and Breen ships compensate for this?

I think you are fine. The Dominion is a jack of all trades. They have ships that can do everything the allies can do.

So it's not as it appears on paper, being able to choose from 3 factions for variety when my opponent is left only choosing from one and thereby being immediately handicapped by that?

Not really because the Dominion is basically 3 different factions in 1. If its a home game you can do what ever you want.