Crushthrough maulers are pretty good at killing most shielders, if you know how to foot work
Good point, although I don't think a low-skill mauler has much of a chance against a medium-skill shielder. Shielder will just dodge overheads. So even a mauler doesn't get an effective "+1" to their skill level against shielders. Compare that to Pikeman vs. Cavalry; any pikeman with at least one finger and a set of computer speakers (to hear approaching hooves) should own even the best cavalry.
To a 2H/pole user, archers are their kryptonite. The archer can just kite until they win, even if they don't have skill or looms or whatever.
A low-skill shielder at the very least won't die to a med+ skill archer.
I just want shielders to have some class that can consistently own them (regardless of skill discrepancy) like the other classes have. Someone said that is cavalry, and maybe they are right. However, I only play siege, and cavalry are very rare there. I don't think shielders fear "bonus vs. shield" weapon users, since they typically only have to block once or twice against these unbalanced weapons anyway.
I'd like to see EVERY bonus vs shield weapon become unbalanced, but for the "bonus vs. shield" attribute to be buffed. My suggestion is a chance for a brief 'stagger' effect after a successful block; not long enough to enable a free hit, but long enough to prevent a counter-attack, and to open up the shielder to an attack by a teammate. I'd even trade the damage bonus vs. shields for this.