If you are going to install FCOM, save yourself some headaches and avoid OBMM.
You will need to use Wrye Bash anyhow and trying to juggle mod installs between both can not only be a hassle but problematic if you make mistakes, sometimes forcing you to reinstall and start over.
I disagree. Installing FCOM with OBMM and Wrye Bash together is far easier that using Wrye Bash alone, and it'll save you a lot of trouble if you install MMM, OOO, and the actual FCOM patch parts of FCOM on OBMM because the scripts will select all the right parts for you.
Furthermore, none of the above mentioned parts of FCOM can be found packaged for Wrye bash, so to install them using Wrye Bash you'll have to unpackage the archives, take the bits of the mod you want and move them to a different folder and then repackage them into a new archive. Plus, if you make a mistake doing that you'll have to remove the mod from Wrye bash and do the whole repackaging thing all over again.
You are best off installing WarCry on Wrye Bash though.
And I'm not sure exactly what's meant by 'reinstall and start over', but if you do have to reinstall parts of FCOM because you haven't installed them right, the OBMM scripts will make it a hell of a lot easier reinstalling them.