Stalemate, then they become buddies

Depends on the conditions of the fight. Picard has really strong starfleet ethics and morals instilled in him so he might be limited on what he will do. If there is technology about then Picard will win since he can just technobabble some solution. On the other hand O'Neill will fight like a caveman. He wants to win no matter what so unless JL used some tricks on him I feel like Jack will win.

O'Neill, hands down.

Neither they would make so much out

depends which child actor plays them.....hey wait a minute...😑

Picard would be whinier.

The MPs sent in to arrest the hotheads would win.

I'm team O'Neil all the way.

I'm not even sure Picard would see it coming.

If it were simply the young version of the characters, I'd say Picard. He was a scrappy fighting arrogant young man.

De-aged Picard, despite being young, would be out of practice and be too distracted by things like morality and proportionality.

I suspect this would come down to the setting. Obviously each character has their own home field advantage. Now, if you dropped them both off on an unfamiliar planet with no supplies and gave them a good reason to fight... I think I might give it to Picard. Assuming that they both try to McGuyver up a weapon, I somehow think Picard would be more effective based on the depth of his knowledge. I would definitely watch this episode, though.