He's been caught off guard plenty of times and got out of it, but not because of some great skill, but because he powered up to get out of it. He's not been using his brain for most of the tournament. At least the kids would have probably stuck with the team. They could have taken them into the hyberbolic time chamber to train on strategy before the tournament. Anyway it doesn't really matter. The show is full of bad writing in terms of both plot and characterizations.
Goku only got 'caught off-guard' twice. One we didn't even see and don't know what happened. Only the first one Goku powered up. The other time Beerus claimed that Goku 'drop his guard', he didn't. He just got outplayed and beat the magical girl without even using Super Saiyan.
Goten and Trunks wouldn't have stuck with the same. They would have wondered off while Gohan shouted 'Team work!' and mot likely get ringed out in the first minute. Also, the Hyperbolic Time Chamber doesn't give you arena experience or battle experience. Trunks spent a year in the Hyperbolic Time Chamber, but was still an experience fighter to the point that he didn't even noticed the weakness in his Ultimate Super Saiyan form.
And saying 'bad writing' is kind of funny when the show points out why Goten and Trunks are lousy choices for this tournament and history backs it up. Remember the characters counted on them to take out Buu, and we know how that ended.
Gohan was scared the entire saiyan arc until piccolo died,try to rush freiza outta anger, didn't fight cell at full power because lol peace,dicked around with cell because lol I'm strong. I don't wanna hear it
Gohan was forced to fight since they needed literally strong fighter they could get their hands on and even then it was
Piccolo's idea. Krillin was going to take Gohan home and even pointed out when Piccolo chewed Gohan out that Gohan had no business on a battlefield.
Namek, literally no one was expecting trouble. It was meant to be a simple trip.
Cell Saga, do you remember how everyone tore Goku a new one for putting Gohan on the front lines? And Gohan's arrogance bout is no worse than Vegeta or even Goku's.
And yet krillin was knocked out in the same way yall saying the kids would be so what's the difference
He also had two assist, one knockout, and saved 18 from a ring out. I doubt either Goten and Trunks would have done as much.