Messages: 3875
FFA wasn't focused on multiplayer. Multiplayer was added.
Infact if you look back to PS2 R&C3 was built from the ground up with to goals: Show off the PS2's online multiplayer abilities, and deliver a solid story. As a result the story suffered from less content, and was shorter than if there was no multiplayer.
By the time FFA came around Insomniac had done mutiplayer tons of times on PS3 with all of the Resistance games, Fuse and A4O. FFA was just going to be a small adventure for the PS3 that would try out a new gameplay element, but later they realised it would be great to do some multiplayer!
The thing about FFA was that it originally has 3 maps, and was expanded to have 5. I believe it had a lot of depth in the gameplay, although because I never played R&C3 multiplayer I can't really make much of a comparison, but I can safely say FFA has far less bugs. Remember that while they spent ages on R&C3s multiplayer they couldn't update it with patches, whereas FFA did get stability updates and stuff.