Actually I feel with sasuke teams, you're throwing the dice to be able to kill your opponent before sasuke dies. Ukon isnt the weak link imo, opponents will take out sasuke because of his strong offence with chase/control, and his weak defensive stats.
You have to see when you fight, assuming best scenario and you get sasukes barrier off, can you kill off an equivalent meta opponent in r2? Considering kiba and ukon dont benefit from the barrier. this lineup and you have only 2 sword wielders, you dont have the option to go sword talents or lightning talents as it is sub optimal. Without an iruka shield (granted I know this is a pay ninja and not everyone has him), I rarely see sasuke surviving past round 2, especially since your lineup doesnt have control immunity. The moment your main (which is pretty much your only control initator) gets controlled, since you have no debuff you're almost certain to lose in r2.
*ternate lineup which you could use with all farmable ninjas is Sasuke, Kimi, and Jugo, while playing sword talents. Jugos shield increases sasuke's survival chance, though ofc Iruka is a superior replacement for jugo. Problem with the jugo lineup is the slowness which doesnt always fit lightnings style of play, but at least I feel you stand a better chance, particularly against fire/earth teams where fire will outcontrol you, and earth will outgrind you.