Q: specifically the fact that they're over an arpeggio of a different chord. (i'll totally accept "i just wrote random chords and it sounded good" as an answer btw)
A: random chords usually don't work. what seems to be happening in the bridge of long long journey is quite a common phenomenon. if the song is in F#, imagine we've jumped to the key of A except we're never using the 1 (A) chord. this happens all the time in these sorts of sections. Also it's not an arpeggio. it doesn't repeat