Maybe NWBO wanted to get the cash and Cancord was the most vulnerable and the strategy is to increase the pressure on the other lesser defendants to settle.
What makes you think that the lawyers aren't "pressing the advantage". You don't know the terms of the settlement so you are guessing with assumptions that fit your narrative.
There are many possible reasons that the lawyers chose to settle with Cannacord. More good than bad, but we just don't know.