for me, the average 25 nl player in this spot is someone who will :
- b/f flop w/ JT/QJ/KJ/TT/99/some AJ/ some small FD
- b/c flop w/ some AJ/ some small FD/ some NFD
- b/3bet flop w/ JJ/55/22/some NFD/ some AJ

and this ranges are aproximate also for non diamond turns.

that "some " in my opinion is "sometimes will fold/call/3bet".

math cant be exact, you are right, but counting combos that bet flop and will bet or c/c turn when we check flop on non diamond/ diamond turn and doing the math for those will reveal that calling flop vs a villain w/ ranges aproximate to ones i wrote is better then raising flop.