You are forgetting that Rick and his group were different then. Plus, Rick and his group had other problems to deal with when fighting Woodbury while Terminus had the unfortuante pleasure of suffering from their unabided attention.
Plus, everyone in Terminus were accustomed to eating human meat and everyone was armed. Woodbury had both soldiers, civilians, and even children and therefore at a disadvantage. Gareth had the unquestioned loyalty of his people while Philip's people were willing to follow him but not fight for him.
All true and Woodbury was built more like a fortress. I believe Woodbury would win, I just needed to say something in favor of the Terminians to try and dissuade this discussion from becoming one-sided.
It depends on whos turf they were fighting on tbh. Terminus was a compound just as Martin said. If the governors group tried to sneak up on them, they would of been sheep. If Gareths hunter group tried to infiltrate woodbury, they would of been spotted and woodbury had more soldiers, therefore Woodbury would win. HOWEVER, if both were out searching for supplies and had ran into eachother, Woodbury would win. So, I have to give this fight too Woodbury.
Gareth and his people lasted about ten minutes. They were scary because they were cannibals, Rick and the group are scary because in general, they're willing to do what they need to do in order to survive - scary people indeed. :)
Terminus, because they were strategic and everyone seemed to be trained/had a role in defense/offense, etc. Woodbury had too many civilians who were untrained and inexperienced, they only had ~20 fighters whereas Terminus had maybe 50 or so.
If all of terminus had a role then it didn't show when they were destroyed - completely - by Rick's group. Actually just by Carol. If the rest of the group had already been dead when she attacked terminus would still have fallen. They weren't able to respond to contact with an actual enemy, the Governor would have had them for breakfast!
Although they were both strong, Terminus might have an advantage. If they were out by themselves outside their bases, Terminus might win. The Governor led his troops into a fortified prison, and his giant army was forced to retreat because a very small amount of people. When the Governor started killing his ARMED men, none of them defended themselves. Against the cannibals of Terminus, They would probably retreat. However if it was the RIVER CAMP, then the Governor may have an advantage. They had both a tank, and many trigger happy men. Those men were much more eager to fight and Ricks group hadn't even attacked them. Taking out the Governors men would have been easy, but killing that tank would have taken Terminus a while.