"I am told the Tank merc can handle multiple red con mobs (I've read claims of 5) until 60ish."
My approach in the merc era so far has not utilized this feature, but I have heard the same from others. My only word of caution would be, if it's a Silver/F2P account, take it easy before trying this approach. I have a feeling that everyone I've heard say this is speaking about J1 mercs, and not the apprentice level ones.
Tat