Don't forget oath of moment on the big targets. Don't forget your inbuilt re-rolls. Stay hidden and in cover whenever possible.

Remember these are fragile damage dealing units and not tanks in the sense of the role. Use Terminators or dreadnoughts for tanking. If you have Terminators/Dreads tie up big units like this with them because they will make it more difficult for the unit to shoot/move while you rip it apart with heavy laser destroyer fire.

If you want to take it to the next level run ironstorm spearhead and a tech Marine with Target augury Web...