I recently reinstalled Oblivion, Wrye, etc... and popped in a few mods including OOO and MMM.

I saw a few things about FCOM.

Do I need FCOM for both OOO and MMM to work?

If so, do I need to install the other 2 mods in FCOM to use it ? (Warcry and the other one)

You can run OOO and MMM together perfectly. It's what I tend to do in most of my games nowadays. FCOM combines OOO, MMM, Francesco and Warcry. The backbone of FCOM is the OOO and MMM setup you already have. Using FCOM will add more gear and more enemies to your game (especially at higher levels) but it won't significantly change gameplay from what you're already experiencing with the mods you're using now.

Thanks for the detailed answer o/

OOO and MMM work together, but you have to do so me special tweaking. Search this forum, there should be a thread specific to that/.

Um, what tweaking are you referring to? I did a search but haven't found anything appropriate to OOO and MMM alone.

I think he means that you need to make sure that you've selected all the MMM for OOO options when installing MMM.

if you use the mmm omod it makes installation really easy and simple. Gets you the correct .esps and helps you decide which extra .esps you want.

Well, that - along with being extra careful which MMM options you install (because of redundancy/conflicts) - and, most likely, correctly renaming the MMM BSA file.

See the current MMM thread's OP for further details.