You sure can (at least with subversion - I imagine perforce will be the same).
I work this way when I work through a slow vpn connection. It is still a good idea to ‘lock’ the shared files if there’s a chance the other might affect it somehow though (eg. the other person renames an asset referenced by your blueprint file, and your bp has to be updated …).
In a small team, it’s perfectly doable, just less safe.