Seems like you could sneeze at a Leo and it'd go boom also.
Jokes aside, excessive use of stock footage is not a good indicator of a suit's capabilities.
In universe, inexperienced pilots getting sneak attacked by overpowered mobile suits also isn't a good indicator of the Leo's performance. Keep in mind that Zechs managed to lock up the Wing Gundam with a Leo in his first encounter. If there had been more pilots willing to perform such a risky move, the Gundams would've been taken out much earlier; one Leo manages to get in close enough to stop them from moving and the rest can cut them down with beam sabres.