CCG deckbuilding is a constant battle for consistency. In any card game, the key to victory is having a cohesive strategy backed by a composition of cards that can reliably execute that strategy. When you play a game, your opponent is the other player; when you build a deck, your opponent is variance.
Abandoned Quarry is a fortification unlike most other fortifications in 40K CCG. It doesn’t quite do a lot itself during a battle; rather, it’s more about what it does for your deck. Granted, the R ability is not inconsequential, but I reason it’s not why people would want to play this card.
For those decks that heavily rely on infantry, fortification synergy, and assembling combos, Abandoned Quarry fills a niche to a T. At a sector with Abandoned Quarry, your command hand offers another four draws to get an infantry unit that will aid you in that battle. Specifically for combo-builders, you get to dig four cards deeper into your deck. Magic players will understand the value of this kind of deck manipulation. In a fashion, Abandoned Quarry resembles cards like Ponder or Impulse.
Is your lonely Bunker Complex looking for a Squad Tanium to really shut down the opponent? Is your Manticore looking to buddy up with a Kane’s Squad for increased rallying shenanigans? Abandoned Quarry is here to help you out. On top of that, you get a primo firepower/armor boosting tactic out of the deal.
However, just because you can trade places doesn’t always mean you should. The situation may call for that extra fortification, such as Squad Tanium (again), Exterminator’s command line (Destroy a fortification to destroy an enemy infantry unit) or a gang of Veteran Cityfighters (+1 firepower and +1 armor for each fortification you have). You can even negate a negative command line like Veteran Skarboyz by dropping it onto the sector to give your opponent a rude surprise.
Granted, not every deck wants fortifications and may be better served by playing another unit instead, but for those decks that thrive on fortification synergies, Abandoned Quarry is quite the find.