"Power" toms (at least back when the term was in its infancy) typically refers to drums where the depth is 2" less than the diameter - 12x10, 13x11, 14x12, etc. - or deeper.
That Granstar should be 12x13. Tama power toms were 1" deeper than most other companies at the time.When I play in my doom metal band, I use a Sonor Force 1000 kit with 12x10 and 11x13 rack toms sitting on top of a 22" bass drum.
In my 90's cover band I play a Tama Granstar kit with 11x13 rack.
For big band and RnB....standard sizes ( 8x12, 9x13, etc...)