Can't win if you roll 1's

That's the truth.   Objective was to destroy all the buildings, of which there 5

Firestorm...did nothing
Stratagem was s10 hit on all the buildings, did nothing.

First round of shooting... many shaken results, one destroyed building
Lost some tanks
Second turn slightly less shaken.  One more destroyed building.
Third turn all went a bit wrong.
Guys had to get out of  immobilised death trap tanks to get in melta range   Blew up another 2 buildings,  guys were in the open so went for assault, which never quite worked.  Was my last worthwhile option and left me no melta left.  Lost their with two more to destroy.

Need to rill a lot less 1's . didn't roll above 3 on hardly any damage rolls.  Destroyed many lascannon emplacements.