Potentially unpopular opinion here, but isn't 750 in five years across two countries fairly small? It's around 16 cases per year per country. Also note these are allegations.
I think it's incredibly unfair to say that police forces are magnets for male rapists (without going into the fact the statistics are about sexual misconduct and not rape). The overwhelming majority of male police officers are good people, trying to help and make a living. This kind of commentary is disrespectful and damaging to men.
I shouldn't have to mention that I do not support sexual violence against any person, but I'm saying it anyway for clarity.