Some people have put too much emphasis on Teemu and Saku staying together. If BB finds 3 guys not named Perry or Getzlaf who can light the lamp consistently they will play together a lot...whether we call them a third line or second line.
There is too much debating over who is third line caliber and who is second line caliber. It doesn't matter. The results on the ice will dictate the TOI any line gets.
Just my 1/50th of a dollar.
YMMV