i like having gore regardless of whether dyson is starting. to start with, yost is more likely to start dyson if gore is on the bench. that alone makes him worth having on the roster.
secondly, it just seem like in games where you need a pinch runner, oftentimes, you could easily use two. like you may have 4 games in a row where a pinch runner doesn't make sense (though with dyson, it always makes sense as a d replacement late with a lead), but then you have 1 game where you could actually use two or three.