The entire Saru progression is wacky. Last season they really played up the Kelpien flight or flight syndrome. If we sense any danger, ganglia extends and we get the hell out.
And he makes it to Starfleet lieutenant? How?
I fully expected scenes of a Klingon destroyer on the main viewing screen, the captain orders Saru to raise shields. No response. Camera pans over and Saru's station is vacant with a quick cut showing him in the fetal position, crying, hiding in his botanical closet behind some ferns.
Captain du jour - SARUUUUU, WHERE ARE YOU!!!