He's getting about 20 secs more a game than Zaitsev, he's clearly first pair PK, but "far more because the LD can't" isn't entirely accurate, Zub gets a min less a game than Zaitsev, Hamonic even less than that since joining us, not because they can't PK, but because the first unit always gets significantly more time. Mete, Brown, Zub, all have 2nd unit PK TOI/game, Hamonic has had 2nd unit PK TOI since his arrival too.
There's not really an issue with playing two RD on the PK, we've done it for a while now and lots of other teams do it too. We are currently playing Brannstrom as our 5th PK dman, Chabot occasionally plays that role too, though with him we try not to because he's already playing 26 mins a night. Sanderson will almost assuredly play PK from the moment he laces them up too.
We have lots of guys that can play a role on PK, Brannstrom has been doing fine in his limited role the last dozen games or so, if we lose Holden it's not the end of the world, though it's always preferable to have as many guys that can kill, we'll still have Zaitsev, Zub, Hamonic, likely Sanderson, and frankly Brannstrom in that 5th slot isn't bad though I wouldn't want to rely on him as a primary option. Thomson and JBD both should be able to PK in a pinch should they get called up too.