Yes there's an imbalance.
There's also a lack of many things, casters only haveing access to staffs (That they wear on their backs like idiots), but no other arcane foci.
There's at least one magic short sword I've found, so they are in there. (Magic as in "not just +1"), but of course there would be an imbalance in that regard if you think about it. If every weapon type had one magic item each, then there would be less finesse weapons which are also magical, because there's less finesse than normal weapons.
Yep, very early in the game I believe the first 3 magical weapons I found (not store bought) were ALL 2handed martial weapons. By the late game, I had found at least 3 unique staffs.
How odd, since the first item you should be finding is the spear in the chapel. Spears aren't Marshal weapons. The spear would be AMAZING if Larian made them actually versatile as they are supposed to. Great for Shadowheart and other clerics/shield users.