Min battery is completely dependent on usage. I can run my 8th scale XT8 truggy with a battery capable of only 30A all day with no problems....
IF I gear low and apply gradual throttle input (no, that isn't fun, but I could do it). Then again, I could gear a truggy to the moon and hammer the throttle and could blow a 150A battery.
My advice: err on the side of caution and go with the 125A figure. The only thing that will cost you is a few extra dollars for a better battery. Heck, to be really safe, go with a 200A capable battery.
Or, use what you have and run the setup with a logger. Look at the graphs after running the way you plan to run all the time. If voltage is dropping too far under acceleration, you lose a lot of usable capacity before LVC, get false LVC trips, and/or battery temps are too high, then use a better battery.