Is this a/c not designed for rough short field ops? That would factor in some extra strength into the u/c components.
Well, less so than DHC's "bush planes" up through the Dash-6/7. An intentional decision, after weak sales of the Dash-7, to emphasize operational cost and cruise performance over short/rough ops.
Not by a large margin, and I expect the original DHC8-100 was still overengineered. But one wonders how much leeway was lost in Bombardier's doubling of the landing weight in the -400s, especially if maintenance was less than perfect.