While
Siege Modification has a permanent effect on the board and can be used multiple times in a game,
Armed and Armored activates only once, probably waiting for the final beat. Like other finishers (
Overrun and
Temur Battle Rage to say a couple), it's an easy target to counterspells or Fog-like cards (who named
Batwing Brume?). Instead, by relay on other permanents to attack and defend is a safer strategy that pays on the longer run.
Veteran Motorist is probably the best example here and it fits the strategy absolutely perfectly.
As a removal I'm using
Caught in the Brights. Ok, it's a bad card, but suits the theme very well and it's cheap af.
I also wondered, but you can't actually crew with summoning sick creatures, which makes creatures much worse for that matter, I think.
You can actually crew with summoning sick creatures. The crew effect says: "
Tap any number of creatures you control". So it's the vehicle effect that taps your creatures, not the creatures themselvs that decide to tap. Exactly like the effect of
Dispatch.
So you can cast at turn 2 the
Heart of Kiran, then at turn 3 cast the
Veteran Motorist and tap the Veteran with the crew ability and attack with the Heart.