I prefer the shield variants as well, it helps your team tremendously to shield them from attacks. I use the axe version, which although cannot AOE, has armor penetration to kill sturmvermins/commanders. Besides, your mates should be taking care of the adds while you are shielding them.

What I usually do is to turtle up and let more of the rats come around me before I do a big push, then go up to the nearest one and hit a couple of times before blocking again. It's a rinse and repeat tactic, but it's proven very effective for me so far!

Also, the basic shield still has stamina for 5-6 "pushes" where you swat people away...seems to give lots more ability to deal with swatting away big crowds!

Charged Attack for Axe+Shield has AOE damage + knockback.
Normal Attack for Hammer+Shield has AOE damage + knockback.

Both Shield variants are good and depends on what you enjoy. Hammer is better for clearing masses while Axe is better against Commanders/Sturmvermin.