I think you're confused about the Yuna arguments in general.
Pro Yuna Arguments: Yuna goes first, summons an Aeon, that's that. Kratos can't slug through that many Meat shields (especially since they have a lot of damage too, Anima in particular) before going down first.
Pro Yuna Arguments #2: Some people don't allow Aeons normally. However, they do allow Yuna to use Grand Summon and have an Aeon use an overdrive. Kratos fails to kill Yuna's turtling strategy before she uses Grand Summon and kills him outright (as was noted, Aeon Overdrives do sick damage.)
Yuna Loses Argument: Aeons are not allowed at all, Grand Summon be damned, so Yuna can't really hurt Kratos (Holy, her single way of doing competent damage, is being nulled out here), and since Kratos can replenish TP by just attacking, he has limitless resources with his healing to counter Yuna's incredibly bad damage. Eventually, Yuna runs out of MP, while Kratos does not, and thus, Kratos beats her that. Dark Touch was just a funny point brought up as to show how sad of a fight it is should you see Kratos winning (since it means Kratos beats Yuna on 10% chance hits...)
So...the whole fight is an interp call on Aeons. Far as I can tell, most people allow them, which is why Yuna respect is so high.
Summons, for the record, in FFX are instantaneous actions, and don't even use up the turn; Yuna summons, and the Aeon gets a turn instantly. At the same time, Yuna can't be hurt by any damage while the Aeon is out; this is why I used the term "Meatshield" before. The fact that Yuna has a bunch of them means you have to be really good at surviving to get through all of them and THEN take her out, or be faster than her and stop her before she gets a turn (be kill her outright, or use some sort of status like Sleep that prevents her from acting. Some may argue Suikoden Silent Lake and ilk would be enough too.)
So...yeah, they have no charge time, and don't even take up Yuna's turn, and make her invincible to all attacks until the Aeon dies. Hence the reason why the philosophy of "If Yuna gets a turn, she wins" exists; there isn't really any one in the DL who can beat her who lets her get a turn (on top of the fact that she's naturally fast too.) Those who beat her are the likes of Sephiroth, Kefka, Tir McDohl, etc. who out speed her and can stop her from getting her game going on her first turn.