Now I played Crisis Core, which I found amazing but I felt some controversy with the last part of CC just for the fact that he got killed by them and not one of the soldier members. Before he even made 1st class he was able to battle with Ifrit and Bahamut. When he reached 1st class before he even got the buster sword, he was able to defeat Bahamut Fury and the Genesis Army. He took on Genesis Avatar and beat Genesis but when it came to taking on Shinra's infantry, he got killed by them. I know that he wiped out most of the army before being knocked out by the remaining 3 infantry men but all of them should have been wiped and on his way to Midgar Cloud and Zack goes.
And if he did make it to Midgar, He should go in disguise. He should have taken on a Shinra infantry uniform with him as a disguise(Like Cloud did in the main FF7) just to reduce the commotion. Of course, he could have hid the buster sword some where and had it retrieved later on, I know he was dedicated to Angeal's idea of Heroes and Dreams but that could have been planned off better for him to get to Midgar, get things right with Aerith and join AVALANCHE as a mercenary. Still, the fight with Shinra was confusing.
Now going back to the diguise, he could have knocked out one of the infantrymen put blood one the sword, give that to shinra army as evidence and sneak into Shinra HQ to retrieve it but still remain in disguise. And Cloud could dress up in Shinra Infantryman as a casualty. Just have Zack equipped with the 1st sword he used, a machine gun and some materia and he'd be action!
Then Join AVALANCHE, save the planet and really fulfill his Dream as the HERO that Angeal was talking about.