The short explanation is that linker1 is the most efficient choice in terms of what you get for what you spend. Taking c2 or c3 is if you want a character to highly specialize in party control imo
I made a linker2 character in order to compare 8 vs 5, the problem is that’s all you get. Its still 22 seconds between joints (enemies die long before that so increased duration on joint is null) and a pitiful duration increase on hangman.