OP said Broly is "as strong," so it's likely that Broly is starting at SSB Gogeta's level. Literally no chance for Jigen to win this.
Most of SSB Gogeta's attacks wouldn't/couldn't maim Broly let alone disintegrate him, so odds are Jiren can't oneshot Broly and prevent his growth. If he isn't already, Broly will naturally scale to become stronger than Jiren under these conditions. I think OP is saying Broly's "as strong" as we last saw him. An equivalent phrase would be something like "the old snake is [just] as nimble."
UI Goku only has his reactions boosted. Every single one of Jiren's attacks were essentially failing to K.O. base Goku's body. Broly is going to tank everything Jiren can throw for days, so he's winning even if he starts on the losing side. The leaps between Saiyan forms are also super drastic, so Broly could be as strong as Red or SS3 for all we know.
The problem is, we don't know how much of a power boost UI is compared to SSB fusion.. UI is just technique that appears to be a power boost but we all know fusion IS a power boost..
Lol I guess we’ll Agee to disagree..
This is acceptable. I don’t want to downplay Jiren by any means but Broly is solely meant to be ridiculous.
Lol are you really trying to apply logic into DB Heroes?
Applying any type of “because the fans” makes your argument excessively dull... If SSB wasn’t needed it wouldn’t have happened whether the fans wanted it or not they soundly implied it for a reason beyond the fans no matter the why behind it.
Dull but facts all the same. Theses been countless battles where fighters used there full power when it wasn’t needed, so your response is moot. SSB Gogeta was overkill... literally.