I’m really interested in this, do you mean “collection strength” is the sum of the fs of what is on the map? Or is it the sum of “your top 20 fighters” (which may or may not be on the map)?
Edit: also, whats the min/max “range” of that collection strength comparison? Because, for instance, i’m currently in gold 2 rank and i’m facing against a diamond 2 with over 150 rift rating above mine while also having a base with an fs sum of 385,4k while mine is 301,69, a difference of 84k fs!. Looking at said player’s profile you can see that all his top chars are diamonds over level 50 (except for a single silver) and a couple of them are maxed, while i dont have a single diamond at level 50 and only 3 of them are over 40. So...?
Edit 2: and again, another match, and the other player has over 40 rift rating above mine (not so big of a difference there) and an fs sum of 380,8k while mine is 301,69, meaning close to an 80k fs! difference. Top chars in profile include several diamonds above level 50, the rest over 40.