There’s a Steeljack for every occasion.

These are the abominable intelligences the Adeptus Mechanicus warned you about, rangy paragons of martial prowess used to anchor the battle line or smash into the breach. With a 2+ save and a Preymark Crest that grants Precision when attacking enemies entrenched upon an objective, you can arm them either with heavy volkanite disintegrators or autoch-pattern bolters and plasma swords.