Exactly. If you were trying to say that because the UEF has a smaller fleet than the GTVA, they can't resist to the Shivan, that's true but doesn't help much since the GTVA itself wouldn't resist to the Shivans either.
If you were trying to say that the UEF is militarily inferior to the GTVA, then yes they are, but they're nowhere near defenseless pacifists. They have a small fleet compared to the GTVA simply because they had nothing to defend themselves against besides the Gefs. Even with a comparatively small fleet, and a comparatively inferior technology overall, they managed to hold against two fully-armed battlegroups hardened by two wars, with a single fleet, which isn't a small feat for "pacifists", especially pacifists that haven't seen a war in 50 years.
Besides, it seems pretty obvious to me that if Ubuntu spreaded to the whole GTVA, now knowing the full extent of the Shivan threat, they would spend much more of their resources on the military front - even more than the already huge amount they spent while being completely isolated and having no threat to defend themselves against (three 3.5 km long destroyers and squadrons of freighter-sized fleet bombers aren't exactly what I'd call police and peace-keeping forces) - so the whole "Ubuntu would leave us defenseless" argument is pretty much retarded to me.