They can't change the Ensign Engineer to Lt Engi. Something has to give for it to remain a legal ship if they do. Do you want to forgo the Lt Tac, or the Lt Sci? It's a "Tactical" Warbird, so the natural choice is the Lt Sci.
So Lt Sci -> Ens Sci, Ens Engi -> Lt Engi. You now have a choice of where to stick your LtC Uni, making any choice workable, two of which are at least distictictive ships (Going LtC Engi anyway makes your ship the Mogwai).
Unfortunately, that boat has sailed, so now you're stuck with this fake choice...only a second Uni can really give us options now.
I'd prefer giving up the lt commander universal and changing it to a lieutenant universal in order to bump the engineer up to a lieutenant as well. That'd give this ship one commander (tactical) and four lieutenants (tactical, science, engineering, and universal).