We're clearly watching different teams. I'm watching the one where Del Zotto was the #4 (and often higher) D on this team for the last two years. Every single stat corroborates what my two eyes are telling me. I will not agree to disagree, because your position is based on absolutely nothing. Del Zotto has had more points, more PP production, more ES minutes, more PP minutes, more PK minutes and tougher match ups. There is literally nothing at all to support your idea that Stralman is anything more than a #5/6 defenseman.
Who out of the following will be sitting or demoted to bottom 6 after you acquire said LW? Stepan? Callahan? Nash? Richards? Brassard? Hagelin? Kreider? MZA? That's 8 guys who will likely, at least at some points during the season, get top 6 minutes. That's not even taking guys like Hrivik or Kristo into account.
Hags Stepan Nash
Richards Brassard Callahan
Kreider Boyle MZA
Pouliot Moore Dorsett
Powe Miller Pyatt
Asham Mashinter Kristo
Those are all guys who have NHL ability (with the possible exception of Mashinter). Leaving Mash out, that gives us 5 extra bodies at forward. Keep a spare or two, and you still have three to four extra forwards. The ONLY place where it makes sense to subtract from the defense to add to the forward pool is in your imagination, with your irrational take on MDZ as a bottom pairing D.
Incidentally, my bet is that Kristo or MZA solidify a spot on the 2nd line RW, giving us a top 6 of:
Nash Stepan Callahan
Hagelin Richards MZA/Kristo
Kreider Brassard Kristo/MZA