hopefully you can measure your road bike and compared numbers to the xs Troll and hopefully things match up closer for you.
That is how I figured my Troll sizing, and it worked out well. Since I was not running drops on the Trucker, I just took the effective top tube length, plus my longish stem, and looked at where that put me in the Troll frames, assuming I would want to run a shorter stem. So far fit seems very good, although I suspect a size up might have worked, too. Nice thing is that with a wide variety of stems, you can make a lot of things work as long as you don't go too big in your frame choice.
the horizontal dropouts on the Troll are something to consider re fenders, and specifically having lots of clearance to remove your rear wheel for a flat (as you have to pull it out far back) but I seem to recall folks on this forum in the past with Trolls saying thats its doable.
I haven't had to remove my fenders yet to change a tire, but I also left the fender clearance high. I recently tried to tighten that up a little, so we'll see. But, for me, this would never be a consideration. I'd much rather have horizontal dropouts and have to loosen the fenders to change a flat. Maybe if changing a flat was a more common occurrence, I'd have a different opinion.