I don't know how to deal with the lack of player-skill involved in the "forcefields" that we call shields in this game,
and I agree that the "shield/dagger ninjas" were annoyingly imbalanced as far as cost-effectiveness (not to mention immersion / realism),
but completely
removing the ability to use dagger with a shield is 1 step forward and 3 steps backward imo.
shielddagger is not so game-breaking, imo, that extinction of the "style" which
no-shield-with-daggers would cause, is needed.
For more
in-depth analysis ramblings, see spoiler below.
If you are looking at these daggermen as sneaky rogue/assassin backstabbers like in some D&D style class system,
then medium & larger shields do not make much sense;
a rogue would not usually carry a big, cumbersome forcefield (shield) around.
He/she would carry more maneuverable, lightweight, concealable equipment instead right?
Also since Warband is more of a big-melee-battle game and not a 6v6-or-smaller type game, then the sneaky rogue/assassin class doesn't fit,
but whatever; call it swashbuckler or light infantry, call it whatever you want;
any person who planned to live longer than 5 seconds, would still probably want the option of having a shield when going into the chaos of battles size Warband simulates.
Even more importantly they would not pick a dagger-like primary weapon as it is too short to very effective in a battle of armies.
Daggers are perfect backup weapons in every situation though.
So... conclusion?
Since we don't have dual-wield or whatever a backstabber-type class would probably use, we have only small buckler-type shields,
we need a shield that looks like a parrying weapon but acts pretty similarly to a small shield?
That would be aesthetically pleasing at least.
Best solution given the game engine's restrictions currently? Nerf daggers' damage! GJ & thanks devs for beginning that process.
What about adjusting the shield penalty versus shield skill some more,
so that with shield in-hand, if you want to be good at anything other than standing still (or riding) and blocking, then you need to have more shield skill? (4-5+? just example)
Or maybe it is already like that, I do not know... I haven't played Crpg shielder in years.