I want everyone to have a gander at Super Robot Wars, any of them really but I feel Alpha 3 makes it's point the most felt, now these games are by no means 'contained' it's a big universe spanning war between some of the most over the top robots in all of existance. But it works in THAT setting and even with your army the final battle still feels FINAL. Your cast come from every different walk in life, a highschool student who stumbled into this mess by accident, trained soldiers, those related to tragedy, an alien general, a cyborg and his AI robot compatriots all fueled through sheer determination. And yet they present this in a way that for this universe? it's believable.
I can believe that Shinji Ikari isn't a total wuss who's going to cry because the people around him are good, positive people acting as friends and mentors. I can accept that the premier Super Robot Pilot Kouji Kabuto can sit down and have a nice chat with Amuro Ray. Because even though there as different as night and day the universe makes it believable.
Now 'Believable' isn't the same as 'Realistic'.
I can BELIEVE that an alien race named the Balmarians actually exist in this universe with there own alien social structure and unique tech level. And I can believe that they present a threat to the heroes of the game. I am not under any illusion that it's 'realistic' it is NOT realistic for a delivery boy no matter how good a martial artist he is would ever be allowed to take his giant robot to go beat aliens. It's not realistic that so MANY fantastical varied robots can all exist with such varying tech levels.
Why use GM's when you have Jeigans? How is Daitarn 3 a 120 foot tall transforming death machine when a gundam is only 18 feet? and how can they fight along side Arm Slaves which are only a measly 8 or 9 feet tall?
But we accept it because the universe makes it believable, even if it's unrealistic.
In Starwars I can accept that a paladin with a laser sword can fight a deathknight with a laser sword. you made it believable even if those weapons could never really work and people could never really have those powers.
The Death Star destroyed by 1 ship and a missile? completely believable even in real life when such a huge target could be taken out by a single ship.
Force powers I'll buy, hell I even buy Cade Skywalkers healing/harm powers in the Legacy comics because it seems believable siunce NOBODY TREATS IT AS NORMAL, they treat it as a frightening force that should not be tapped and is so far off the slippery slope that it's not worth considering.
Cade can't kill an entire army, he's swayed more between the sith and jedi than most people sway between different meals for dinner and yet it's believable because deep down he's a frightened guy running away from his fears rather than confronting them.
Think of Megas XLR or One Piece, neither of them is 'Realistic' but both are 'Believable'
... well okay One Piece has the Cyborgs which STRETCH Belivability but for the most part it weeves a darn good narrative.
Megas is cheesy and over the top and is in no way realistic. But the characters, there interactions make it seem believable.
TFU and it's sequal weren't 'Believable' and when your not realistic or believable you have nothing.
People said he liked Shadow of the Colossus for the huge boss battles, but within SotC it was believable that a guy, frail and weak but cunning could take down something so large it was beyond scale.