That's a skill/coordination issue, not a gear issue. Try running it with people you work well with, it's not pug friendly.
LI HM is easy to fail if people make mistakes with their tactics. It's not down to gear. It's just skill. 4 people in full columi can easily breeze through LI HM if they know the tactics and execute them well. You (or your group) does not. That's why you wipe.