The important thing for me is knowing where they rank compared to nhl players of that time.
Well that is obviously impossible to know for sure. But like I showed earlier all of these four players managed to prove themselves as penalty killers against the powerplay units of Best-on-Best Team Canada. If you want a somewhat larger sample size it is also worth noting how impressive the shorthanded goal differential numbers of Mikhailov and Petrov were against NHL opponents in the 1972 Summit Series, 75/76 Super Series, 1979 Challenge Cup and 79/80 Super Series. In fact many of the top Soviet penalty killers from the 70s and 80s had impressive shorthanded goal differential numbers in Best-on-Best and Super Series competition as you can see here below.
Shorthanded goal differential from the 72 Summit Series, 76, 81, 84, 87 Canada Cups, 79 Challenge Cup, 87 Rendezvous and 75/76, 79/80, 82/83, 85/86, 88/89 Super Series. I only included players with at least 25 minutes of shorthanded ice time in those tournaments/series.
Petrov: 3 goals forward, 2 goals against over 26 min, 42 sec of shorthanded ice time: +1
Khomutov: 2 goals forward, 3 goals against over 42 min, 35 sec of shorthanded ice time: -1 every 42 min, 35 sec
Makarov: 6 goals forward, 8 goals against over 70 min, 18 sec of shorthanded ice time: -1 every 35 min, 9 sec
Mikhailov: 2 goals forward, 3 goals against over 26 min, 18 sec of shorthanded ice time: -1 every 26 min, 18 sec
Bykov: 2 goals forward, 4 goals against over 45 min, 14 sec of shorthanded ice time: -1 every 22 min, 37 sec
Krutov: 6 goals forward, 11 goals against over 69 min, 10 sec of shorthanded ice time: -1 every 13 min, 50 sec
Zhluktov: 0 goals forward, 5 goals against over 31 min, 19 sec of shorthanded ice time: -1 every 6 min, 16 sec
I would say that the majority of the seven Soviet forwards with more than 25 minutes of shorthanded ice time in these tournaments/series had outstanding goal differential numbers and only Zhluktov had what I would consider below average numbers.
This is how Mikhailov and Petrov measures up to the other top Soviets when it comes to ice time finishes in Best-on-Best and Super Series competition.
Makarov: 1st at the 1984 Canada Cup, 1st at the 85/86 Super Series, 1st at the 88/89 Super Series, 2nd at the 1987 Rendezvous, Tied for 3rd at the 1987 Canada Cup, 4th at the 1981 Canada Cup, 8th at the 79/80 Super Series
Krutov: 1st at the 1987 Rendezvous, 1st at the 1987 Canada Cup, 2nd at the 1984 Canada Cup, Tied for 4th at the 82/83 Super Series, 5th at the 88/89 Super Series, Tied for 7th at the 1981 Canada Cup,
Mikhailov: 1st at the 75/76 Super Series, 1st at the 79/80 Super Series, 3rd at the 1972 Summit Series, 9th at the 1979 Challenge Cup
Zhluktov: 1st at the 82/83 Super Series, 3rd at the 1979 Challenge Cup, 3rd at the 79/80 Super Series, 4th at the 75/76 Super Series, Tied for 4th at the 1976 Canada Cup, 5th at the 1981 Canada Cup
Bykov: 2nd at the 1987 Canada Cup, 2nd at the 88/89 Super Series, 3rd at the 1987 Rendezvous, 4th at the 85/86 Super Series, 7th at the 82/83 Super Series
Petrov: 2nd at the 1972 Summit Series, 2nd at the 75/76 Super Series, 4th at the 79/80 Super Series, 5th at the 1979 Challenge Cup
Khomutov: 3rd at the 85/86 Super Series, Tied for 3rd at the 1987 Canada Cup, 3rd at the 88/89 Super Series, 5th at the 1987 Rendezvous
Considering how incredibly well the Soviet penalty kill generally was doing in Best-on-Best competitions it does to me make sense that the best Soviet penalty killers should rank pretty high on a list of the top penalty killers from this time frame. Exactly how high is very difficult to say though.
And regarding the use of the Soviet players on the penalty kill in the ATD I would also say that it largely depends on what style of penalty killing the team is planning to use considering how much the Soviet penalty killing system was built on puck possession. If your plan is to play a very strict boxplay where the puck is dumped down deep at every opportunity then there are probably better options than the top Soviet penalty killers. However if you plan to use the puck possession tactic as an integral part of your penalty killing then I think that the top Soviet penalty killers are great options since the goal differential numbers here above clearly shows how effective they could be when playing that style. The Czechoslovakian penalty killing system on the other hand used more of a hybrid between the puck possession tactic and the more strict boxplay tactic so when it comes to those players I don´t think that this matters as much.