Hey

There is not many counters to Kakuzu.
You talk about shira, but well, on papper why not. But if he is faster he can interrupt + kakuzu have easy 250%defense scale, even more easy to get if you play the kind of team you suggest.

Hokage minato buff is good idea indeed. Ningendo too but with the original mirror +2 (resistance buff)

Edo itachi is a "counter", where the position 1 is god, itachi will only control failed. Or rarely success. But w/e, everyone running katsuyu lvl3 and kakuzu team have plenty of chakra to clean it. And itachi is too squishy. Even with his 50%nin reduction passiv.

Ibiki is a better counter imo, if he do not get OS by kakuzu myst round1 without any counterplay

Kushina + yagura is a legend (maybe you talk in arena ?). You really think yagura can survive long time enought ? I tried it and nope, since position 1>>> pos2, yagura will die round3 and it will be Kushina vs kakuzu till round10. And since kakuzu have 250%defense scaling, you know the end.

Actual real counters are edo minato barrier + weakness passiv (aka not easy to get) + chakra drain round1 (if they do not get OS or interrupted round1) + weakness debuff ninjas (so not much ninjas, or overpriced ninjas).

Or like the guy said, play the ugly braindead Kakuzu too.