Hemsky has had one good year where he put up over 75 points. 1 year. He has never hit a PPG. Hemsky has missed 96 games over the last four years. Hossa has also missed time over the last four years. Hossa has missed 43 games in the last 4 years. Hossa has scored 288 points in the last 4 years. Avg = 72. Hemsky has put up 212 points over the last 4 years. AVG = 53.
You tell me who you would rather have.
As for a rebuild. Rebuilding with prospects alone will leave you long in the tooth before you can ever compete again. A rebuild simply means trading producing players for younger players. Nothing about it says you have to trade for "Maybes".
And just for interest sake...According to Dobbers guide to the top 300 in a Keeper league, we find St. Louis as the #21 guy. Giroux is found somewhere in the 52, Benn is #133, Filatov is #147.
So take a look. Are you really going to trade the 21st most valuable player for the three to four guys in the #130 to #150 range? I know I sure would not. However, you get a #52 in there, and than add prospects (notice how I have some proven youth in that deal with giroux and the prospects are just the equalizer) it makes much more worth your while. Rebuilding does not mean selling low on production. People will always pay more for production now,than they will for possible production down the road.