At the collector voltage that your system runs the output transistor at, Andrew T used to tell us to use the DC soa rating for how much current a transistor could stand. Lots of popular transistors don't have a DC rating, only a 1 second rating.
When I look at commercial amps with 24/7 power ratings, that are very successful, I see they have done that. The max power rating determines the current the amp will put out on a non inductive resistor, and dividing by number of transistor pairs tells me what they were expecting out of the transistor. As Andrew used to tell us, real speakers sometimes take up twice the current of a non-inductive resistor.
For example look at Peavey Crown and QSC class AB products, which are very successful in a crowded market. You can get Peavey schematics without trying too hard, eserviceinfo.com comes to mind. Also here, but the search engine can't find anything. Loads up your results with the first word you typed in that comes up most recently.
Hint, Peavey 1990's products used MJ15024/25 most of the time. PV-4c, PV-8, PV-1.3k, CS800s, CS800x did. Those usually get huge dust balls on heat sink before blowing transistors, unless a 1/4 phone plug got pulled partially out & shorted the channel.