FFG O.H.Perry is not designed for ASuW. It's typical ASW frigate with limited ASuW capability.
In Vanilla Perry is more powerful because use SM-2 missiles (instead SM-1), better radar and bugged FCR's allowed to launch more missiles than weapon channels.
Conclusion:
If you wanna realistic Perry - install RA mod
Btw: Perry maximum number of Harpoons is 4
For attacking enemy ships you should do this from different directions at the same time with using 3-6 missiles (best mix SM-1, Harpoons and Penquins)
For hiting target by 2 or more Harpoons in the same time you should use waypoints.
For example for 2 harpoons first one should have +/- 8kyds longer way to hit than second. You can do this by placing first waypoint far on traverse.
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