Marci, that helps a bit. My assumption is that each project is linked to it’s own separate SharePoint site. Are you on SharePoint 2013? If you are using SharePoint and Project 2013, you can use a master project if all projects are stored in the same SharePoint site. That I believe is new with 2013. Otherwise you will need to keep the separate project schedules in a file storage (network share or local machine) in order to combine then all.
Then there is the concept of a Resource pool to share resource across projects. Something out of the box in any version of Microsoft Project. Either way, 40+ resources and I don’t know how many projects might be a lot to manage using Microsoft Project as a standalone. I’m not saying it can’t by any means, but can get a bit complex and there are some key best practices to keep the files in tact.
Let me know what you are thinking or if you have any other questions. I’m happy to help.