So... it remains possible to build a heavy-chemistry roster. No way to tell how plausible it is in a seriously competitive environment, but it can be done in single player. Takes much more effort than before, clearly by design.
My current SP team just won back to back titles (while getting a 27 from Herb on roster strength after the second one) with an
AffIndex of 78 (and that ignores the multiple "potential affinity" players we have aboard. There's no way to tell whether this team would be a power team without the chemistry boost (we have a strong passing roster) - it probably still would be.