Really good point. my road shoes are very light and not particularly supportive on the ankles.How technical are the trails you're running on? Summer's round the corner, you might not really need anything particularly "traily" for a good while. Personally I wouldn't have a shoe for both, I'd have a pair for road & another for trail (or just use road shoes on mild trails)
Nothing technical about my trails, generally go off road through fields/ moors and just very variable terrain and often quite unforgiving/ damp in places.