A fun fight, but if you really think that is hard, wait til you get to the train part lol.
Train part is a piece of cake, everythings pretty easy all things considered, with red, cid and yuffie. Get yuffie to mug with added attack then have other 2 spam aqualung or beta for the first fight. Second fight barrier up, regen up, spam laser. Third fight is easier unless you want the warrior bangle then it can take a massive chunk of time up, anyway yeah keep mugging till you have the bangle, while barriering and regening. Fourth fight is also a walk in the park, wall up straight away, then neo bahamut causing 9k damage to each member (with my 213 magic red

) followed by big brawl and all creation/doom of the living if you wish, instant death.
Also the comment about the grand horn, if you are so bad at the mini game that you need to fight the grand horn, im pretty sure you fail the mission
Erm you do realise that if you kill commander grand horn in the final fort condor battle you get an imperial guard don't you? Why anyone would choose to win the mini game on the last match is beyond me when it means you don't get an imperial guard. You also get the huge materia.
EDIT: Also I never realised how close I was to killing the birds, when I could no longer 2 of em I was pretty naffed off cause I thought the targetting was glitching on me, I didn't know when they die they just become unselectable

EDIT: Oh my god my game severely glitched on me there, went to play the game again after posting, I went to nibelheim to get yuffie her limit break bar full. Got in a fight with wolves, pressed start on my controller then it took me to the train fight with the bird thing, the timer was on 0 so it then went to a black screen with only cid and 2 dialogue boxes, one blank one said we're gonna hit north corel, cutscene played then I was unconcious in north corel.......Yeah just wanted to share that lol. Don't think I could replicate that glitch XD
EDIT AGAIN: Yeah I went back to fort condor and was suprised how much I slaughtered them, I used sense this time so I knew how much hp they had left. Dunno why I struggled that much, only about 2 levels higher than before.