Multiple people working on the same PCBs/Schematics in Altium

If two people in the same company are using eagle pcb layout program they can each do so without having to coordinate with each other…but if two people in the same company are using altium then they must go through a multitude of setup features on their PC's so that they can both work on the same schems/PCBs without messing up each others work…is this true?

No it's not, Altium has a specific package called "CircuitMaker" which is specifically intended to facilitate collaboration. You set up a project, add team members to it, and everyone can collaborate on the schematics and the PCB, design schematic symbols and footprints, add comments etc.

This is a difficult task and even OrCAD has troubles. Since they are binary files, repos like Git or SVN (we both use them) aren't fully useful.
For schematic, you can always (and this is the best option) break your design in multiple pages.
If your files are on Git for example, you even don't have to close Altium. Just update and pages from other people will sync.
Of course, don't work on the same page.

In PCB is more complicated. I often do a "master work" in the main PCB file (board associated with project) and others, using the same schematic can route pieces in other PCB file, then copy-paste.

Actually there is a feature called Snippets but not very clever so take care
You can save piece of routed PCB (and schematic too) then use later. However, component links problems will appear.

YO3HCV, Edi