Freeza wishing Broly stronger would be GT levels of awful. @Wellman hits the nail on the head. They did a lot hinting about Broly being special. When King Vegeta taps his birthpod Broly gets so agitated that his power level gets so high that it overloads the equipment. Conservatively, that’s at minimum a power level in the tens of thousands. DB is random but scouting equipment seems to read upto six digits without issue.
That said, once Dragonball got to the Z phase power increases became ludicrous. Goku went from less than 500 versus Raditz to 150 Million when he defeats Freeza. Thats in a little over a year. People give Z a pass for lot of things they wouldn’t let fly today. Fans try to make sense of the illogical. Toriyama writes his story without considering these things and creates a plot device to explain the power creep. I love the Cyborg/Amdroid saga but Gero, with no knowledge of Namek, creating two beings that make Freeza look like nothing isn’t plausible.