It maybe possible that a system using both together maybe better (though having to install both a fusion drive and the antiproton system maybe an issue), but the text given doesn't say that's what happens, it never says antiproton enhanced/boosted/etc fusion drive, it several times says that antiproton drives are the military standard.
Edit: Also the fusion drive text is unedited, it first says that it vents reactor plasma (isn't that rather dangerous and going to degrade the fusion reaction?). Then it says that it reacts the
3He and D and use that to excite the remass hydrogen. So a are you using the fusion plasma as remass or are you using hydrogen? Seriously codex, I like a lot of your stuff, but that's just