One thing I didn't take into account, that is actually consistent, is that Thanos and his lieutenants weapons are all able to damage Vibranium. It didn't make sense to me that Vision would be so easily speared in IW, since he is Vibranium based, but its consistent to what Thanos was able to do to Cap's shield. As warrior aliens, they probably have technology to bypass or resist the properties of metals. Thanos Armor might be more effective then Vibranium.
Captain America/ Thor/Iron Man couldn't really do much with Thanos in armor, but Scarlet Witch was very effective given her limited matter manipulation.