Carleton is right.
I'm trying to be kind here. You seem to be so insistent on explaining how you are correct on a discipline that you basically have NO experience in: the Keirin.
1) How many beginner/intermediate level Keirins have you seen or done in your ~1 year of experience? Trust me, a 52x15 is a fine starting point for a Cat 3. It's not "spinning like crazy"
2) No one is claiming that you should "spin" like crazy when sprinting. It's not like it's some state secret that the current crop of sprinters is using big gears and strength training to achieve some impressive times. But you can't just throw a 50 year old Masters rider on a big plate and expect them to go fast because "big gears are where it's at".
3) Maybe your "team" needs to do a little more studying if they really told you that the 125-130 rpm range is where it's at. It's a bell curve and it's a lot wider. And then when you start throwing in different crank lengths you can easily add or subtract 5rpm on the top and bottom due to pedal velocity correction. 125-130 might be right for you -- it'll show up in a power - pv curve analysis. But even that can vary according to track conditions.