When a responder to 1 NT or 2 NT does NOT use Stayman, the inference is that they do not have a 4 card major.

The chances of success favour leading your 4 card major suit rather than a broken 5 card minor.

The probability is that leading a minor suit will run into dummy’s length.

Lead ♠ 2 (playing 4th best leads) rather than ♦ 5