Voulgiers are a highly defensive troop armed with a halberd. They are excellent infantry that can fight well and hold their own in any battle. The durability of thesse guys is truly amazing. I've done countless battles where the Voulgeirs are surrounded and manage to hold off until I can send in reinforcements. And that's the best thing about the Voulgier I think. They can survive anything. They can't beat every enemy, but they can certainly be an obstacle to any opponent. Try using them on the flanks to trap enemy infantry.