Does the Subaru Boxer Engine have lower HP/L when naturally aspirated than inline or V ones?

When comparing the Subaru Boxer Engine against other engines from Japanese car companies, it seems as if Subaru gives you somewhat less HP and hence HP/L than others? Their 3.6L EZ36D in their Outback and Legacy outputs 256 hp, compared to Nissan's 3.5L VQ35DE in their Altima that outputs 270 hp, or Honda’s 3.5L J35Y1 in their Accord, Pilot, and Odyssey that output around 280 hp. Or consider Subaru’s 2.0L FB20 in the new Impreza that outputs 150 hp, compared to Honda’s 2.0L K20C2 in the Civic outputting 158 hp. Or their 2.5L FB25B in the Forester and Legacy outputting 170 hp, compared to Mazda’s 2.5L PY-VPS in the CX-5 and Mazda3/6 outputting 184 hp (which is quite similar to K24W).Maybe I'm just ignorant of how important HP really is. I'd love to hear your opinion. via /r/cars http://ift.tt/2tzoSDm