First off, you don't 'NEED' baffles in a jeep fuel tank.
Not to be disagreeable, but then I usually am... I will.
Some Jeep tanks (like a poly) have a "well" molded into the tank. It's in this place the siphon is going to sit. The well keeps a little gas in the siphon area at all times.
Which brings us to the "Don't Need" a baffel. In most cases you don't... but what happens you're off camber and need the fuel that's flowing to one side of the tank? Well, the engine sputters, and dies. Hopefully you don't sputter and die.
It's even more important for fuel injected vehicles.