Definitely agree about H/H, though possibly not for the same reasons. Reckless Strike has a 1 round cooldown now, which makes the guardling's movesets very awkward. In particular, you can't afford to take Whirlwind in slot 1, because slots 2 and 3 also force you to take cooldown abilities. This is a shame because Whirlwind is probably the guardling's most attractive ability.
Hawk Eye is extremely bad because a crit only gives you +50% extra damage. With +25% crit for 4 rounds, you can expect to get 1 extra crit in total, which means you spend 1 turn to get half an extra attack later on. This is already bad, but you also have to survive 4 full rounds to get the benefit, which is far from guaranteed.
That leaves you with Crush/Sandstorm plus either Reckless Strike or Blackout Kick, which looks a lot like a more aggressive version of Anubisath Idol (complete with humanoid passive). Reckless Strike plays nicely with Sandstorm because Sandstorm subtracts from your opponent's damage before the Reckless Strike debuff multiplies it. If you go Crush/Sandstorm/Reckless, then you definitely want H/H. Sandstorm and the humanoid passive benefit a lot from health, and Reckless Strike makes going first very bad (because then the Reckless Strike debuff will be present for 2 of your opponent's turns instead of 1).
Crush/Sandstorm/Blackout Kick is potentially interesting, but Blackout Kick demands speed and will make you much less of a tank. When imagining situations where that moveset would be good, I think Anubisath with Crush/Sandstorm/Deflection would almost always be better.
Technically, you *could* go with Whirlwind/Sandstorm/Reckless and then you'd be locked into a rotation of WW/Reckless/SS/Reckless etc. I doubt this could be effective since Sandstorm will protect the opponent's backline and make WW very weak.