Effect returning a monster to hand is good and reusable, but slow.
The problem with Subterror decks is that all Subterror Behemoths are high-leveled monsters, so getting your first flip monster on the field to start Special Summoning can be a problem.
Guardian Statue works well in a Subterror deck by letting the bigger monsters trigger their Special Summoning Effects. He even has a similar playstyle to Subterrors by flipping himself down to reuse his effect.
These monsters have similar types and attributes to Guardian Statue, with effects that similarly remove an opponent's monster from the field. Golem Sentry is basically this card but with higher defense. Medusa Worm is similar but by destroys the opponent's monster instead of returning to the hand.
Tip: If it's got "Guardian" in its name and isn't named in the text of Arsenal Summoner, it's a Guardian. Same holds true for most archetypes, they don't often let things slip through the cracks in that regard. *glares at Vampire Vamp*