I have thought about it for a while, and…
…why don’t we just give the player an option to put the shield on his back on demand f.e. using the special attack key.
This way hammer + shield could turn into 1h hammer with the same attack pattern as 1h weapon and same/similiar damage profile.
Of course to not make the shield combo better than 1h variant without the shield, there would have to be some shortcomings - even with your shield on your back f.e. your dodge count, dodge range, stamina and maybe attack speed/dmg could be slightly lower (I mean, not everything at once has to be worse, just some things) - it’s all logical, because, well, lets face it, shield on your back is a bit clumsy and still weights a bit.
The above change would be rather simple to execute and would fix quite a few problems of shield + weapon combo, f.e. dmg vs boss/armor of shield + mace/hammer (right now it quite frankly is horrible at those tasks, in “shield on the back” mode it would be OK, not high, but OK), v. low mobility making clutch gameplay often impossible, low utility of shield vs chaos spawn - you better dodge cause shield won’t help you, when he grabs you and with dodge count and dodge range of shield, there’s a good chance it’ll happen.
It would give shield builds a lot more utility and versatility, and players would be rewarded by smartly switching between shield and shieldless mode - the more player decisions that matter, the more fun IMO.