Why I let myself get sucked into these I'll never know, but this is by far the stupidest one.
More agile and likely as strong......You clearly have no idea how insanely fast and strong Astartes are. I've always liked this quote from Know No Fear
to really show just how fast an Astartes reactions are, nothing I've played or seen shows the Spartans to have even remotely comparable reflexes.
The Word Bearer is almost unrecognisable. For a nanosecond, the figure registers to Luciel as an unknown, a threat.
Transhuman responses are already there, unbidden. Adrenaline spikes to heighten an already formidable reaction time. Muscle remembers. Luciel wears his boltgun, an oiled black pit bull of a weapon, in his thigh holster. He can draw, aim and fire in less than a second. The range is six metres, the target unobstructed. There is no chance of missing. Maximus plate, frontally augmented, might stop a mass-reactive shell, so Luciel will fire two and aim for the visor slits. The airgate skin-sleeve is self-repairing, and will survive las-fire damage, but a bolter shot will shred it open, so Luciel also braces for the explosive decompression of a ricochet or a miss-hit. At a simple, subconscious neural urge, boot-sole electromagnets charge to clamp onto the deck plates.
He can make a clean kill headshot in less than a second and a half, two rounds for kill insurance, and probably protect the atmospheric integrity of the airgate.
All this, all this decided, unbidden, instinctive, in less than a nanosecond.