Had another thought...
In-universe, Starfleet was formed by a merger of UE Starfleet, Andorian Guard and Vulcan High Command (or it's replacement).
UESF ranks were Ensign, Lieutenant, Lieutenant Commander (mirror only?), Commander, Captain, Commodore, Rear Admiral, Vice Admiral and Admiral (Mirror Black).
Vulcan ranks were Sub-Altern/Sub-Lieutenant, Lieutenant (implied), Major, Sub-Commander, Commander, Captain, Fleet Commander, Administrator.
Andorian ranks are the least complete but include Lieutenant, Commander, Captain and General.
Putting the equivalencies we get:
Fed SF Ensign =====> SF Ensign, Vulcan Sub-Altern, unknown Andorian rank. (no stripe)
Fed SF LT-JG ======> No UE rank, Vulcan Sub-Lieutenant, unknown Andorian rank. (1/2 stripe)
Fed SF LT =========> SF Lieutenant, Vulcan Lieutenant, Andorian Lieutenant. (1 stripe)
Fed SF LT-CDR=====> SF Lt Cmdr (?), Vulcan Major, unknown Andorian rank. (1.5 stripes)
Fed SF Commander==> SF Commander, Vulcan Sub-Commander, unknown Andorian rank. (2 stripes)
Fed SF Captain =====> SF Captain, Vulcan Commander, Andorian Commander. (2.5 stripes)
Fed SF Vice Cdre* ===> SF Captain (?), Vulcan Captain, Andorian Captain. (3 stripes)
Fed SF Commodore* ==> SF Commodore, unknown Vulcan rank, unknown Andorian rank. (1 broad stripe)
Fed SF Rear ADM ===> SF Rear Admiral, Vulcan Fleet Commander (?), unknown Andorian rank. (broad +1)
Fed SF Vice ADM ==> SF Vice Admiral, Vulcan Fleet Commander, unknown Andorian rank. (broad +2)
Fed SF Admiral ====> SF Admiral, Vulcan Minister (?), Andorian General (?). (broad +3)
Commander, Starfleet> SF Admiral, Vulcan Administrator (political appointee), Andorian General (broad + 4)
* = Under this system, Decker and Wesley would be Vice Commodores (Starship Captains who can act as Task Force Commanders in the absense of an Admiral), Picard could also be this rank, Sisko is either this or Fleet Captain during the DW (FCPT being the "Chief of Staff" or "First Officer" of a Fleet Commander). By contrast, Mendez, Stocker and Stone et al, who permenantly exercise higher authority than Starship Captains would remain Commodores.
Also, given that the specific ranks of the admirals in Conspiracy are never given (and several Cdres are listed on computer screens) and their prominence, it would probably be best to assume they either rank a grade higher than they appear to (Quinn is a RADM rather than Cdre/RADM (LH), Savar was a VADM rather than a RADM, and Aaron was a full ADM rather than VADM) or that they are all RADM or better and Savar - as he's in the middle - should be wearing the highest rank.