Its funny how the NFL has never come out ans said "Alright this is how it works"
Last year for instance we lost Schaub,Upshaw and Osemele and gained Weddle and Watson which as we all know in the end netted us a 3rd for Osemele. As of now we've lost Ducasse,Wagener and Juice and have netted Woodhead and Jefferson probally leaving us with Wagner as a 3rd or 4th comp. I know a lot is dependent on contracts but here confusion sets in with me at so to keep it simple lets also say we lose Guy as our only other FA lost and don't sign another UFA. Lets also just say Guy gets a 2 yr 5 mil deal. Okay so would Jefferson cancel Guy(lower contract) or Juice. Regardless we would be 4 lost to 2 gained therefore do we get a 4(Wagner) and a 5(Juice) or a 4(Wagner) and a 6(Guy). What needs to be really known is do they match up contracts or take your highest 2 to give you comps.
Now just to get back to 2016 for a minute. We know Osemele blew away everybody elses contract but both Weddle's and Watson's contracts were well above Upshaw and Schaub's but yet these were the ones cancelled.