I feel they arrive in varied kinds. There’s Par 3 programs the place each gap is clearly a par 3 with common yardage, and with one or two 4s combined in.
The course close to me has 18 common holes, then a 9 gap “Govt/Household” course. It has an additional set of tees nearer than the others. It has 4 par 3s underneath 90 yards, 4 par 4s underneath 240 yards, and one par 5.