From what I know, yes, they are different mods.

Mannimarco Revisited only makes Mannimarco stronger, so it's no surprise that it's compatible with OMG. Mannimarco Ressurection, however, gives you a bunch of new quests and lets you join one of two new factions, necromancers or battlemages, and you have to leave the mages guild for the former or give up the position of archmage for the latter. This seems pretty likely to conflict with the new quests in OMG, but I can always hope.

So has anyone tried using them together?

Yeah, they work together. But I would recommend to play through M revisited before you initiate OMG quests. You have to "fire" the new arch mage though and restore the vanilla bruma guild to its fiery state (but it kind of fits in the story) before you tackle the OMG quests. The creator of M revisited have included in game menus that let you these things quite easily

I personally don't think Mannimarco Resurrection will be compatible with OMG, because it messes with Mages Guild Ranks. Basically you lose the Archmage rank to achieve the title of Chief of the Battlemages (If you do not play as a necromancer), when in OMG you must be archmage to keep playing with the quests added by this mod. I am almost sure they will conflict in some critical ways.

Mannimarco Revised (the mod which makes Mannimarco stronger) is perfectly compatible, though. I'd never play a mage without this mod... It makes the last boss of the Mages Guild so difficult to kill without your brain...

they are compatible, you just need to make sure you do the quests of one mod first before you do the other, so yeah technically speaking they're not compatible, you can make it work though.