Kei is not always going to be using Shadow clone.
- If she's already fought that day or otherwise burned chakra and can't afford it or would be running on empty.
- If she needs to preserve chakra for after that fight.
- If she's injured (copied injuries pop Shadow clones instantly).
- If she's poisoned, the environment is hazardous, or otherwise she's debuffed to take stress/round.
- She's already taken mental stress or consequences and won't beat the Resolve check
- She decides to use that chakra to summon a jonin instead of her middling strength clones
Sure, in an ideal world she will always be topped up and healthy but we should plan for every scenario, not just ones that favor us. For your very specific battle strategy then sure I can see why you don't think it will be helpful, but I don't think it's a good idea to limit ourselves to needing a very specific strategy to win. Jonin supposedly win by diversifying their builds so they have many strategies if their go-to doesn't work.
- How often has fighting multiple times a day happened to Nara Kei? We are not missing-nin, nor are we sent on hugely lethal missions. And with FOOM the only real threats to us will soon be essies and elite jounin. Regular jounin too, but those will not provoke us on their own. There aren't enough threats to make multiple fights a day a realistic occurence. Besides, that applies to any strategy, not just SC specifically.
- Same point as above. There is little overlap between a lethal fight that needs chakra, and one in which making SCs would be ill-advised, because the moment there is any risk at all, you should pull out all the stops and end it quickly.
- If she is injured that is all the more reason to use SCs, because it leaves her all the more vulnerable, so having body decoys is even more vital.
- That is a very, very specific scenario, not something that should generally be planned for in a build, rather something you just adapt to. I mean, sure, sounds pretty obvious that if there is a hazardous environment that pops SCs immediately you won't be using them but that is an exceedingly minor consideration to have in the overall build direction.
- Fail the Resolve check from making clones for an actual lethal fight? With her Jounin Resolve? Impossible at this point, consequences or not.
- Yes, well, that takes a ton of chakra and will soon be less effective due to FOOM and the combination of debuffs stacking. And does not ever really become more effective, while her personal stats do grow. Summoning as such also leaves her far less safe in the immediate period than having clones do the fighting and slowing the enemy, while also protecting her with substitutions etc.
Its not like I'm proposing a narrow combat strategy. There is a lot of things that can be done with Shadow Clones and Shadow Jutsu combinations, and frankly very few things that cannot. Action Economy is king in practically any combat system and mfd is no exception. And then she also has Summoning and Ranged Weapons (which combo well with binding jutsu), on top of that.
