Not that I don't want Sergei and Lats to get the ice time but it's doubtful that they could produce on the 4th. There isn't enough ice time on the 4th line for 40 points in production. Also, with Lats/Kost on the 4th we loose a lot of our physicality and may not be able to respond if another team wants to challenge us that way.
For those two to get back in the line-up they have to bust their butts in practice and produce when given the chance.
Right now, if it's not broken...
bring kosto to the 4th line with begin and lapierre and put sergei/lats on the 3rd line with pleks and tanguay