Just crouch when you swing for easy wins against shields. My main gripe with them is that they're simply not fun to play against as they can completely neutralise almost every attack besides crouches. I feel like the main problem is lack of punishes available against shields, the most effective way would be to circle to their right and swing but due to the nature of the controls in this game it makes it very hard to quickly circle the opponent. A lock on system would solve these problems but I feel like that wouldnt fit the style of the game