I'm inclined to agree. It isn't that STC's Kirk is made to behave like Picard, but rather the writing echoes things that were written for Picard.As someone who's not a Picard fan, I can say STC's Kirk is a long, long, long way from reminding me of Picard.
"The White Iris" is not a TOS story. The characters in TOS could be introspective--that runs throughout TOS--but no stories of that era picked over the scabs of the chracter's souls in the way stories did in TNG and later series.
"The Enemy Within" was a thumbnail study of the duality of a person's character. The basic good and bad aspects everyone has to varying degrees. It had nothing to do Kirk's emotional challenges beyond what he had to deal with in that specific situation.
"Obsession" wasn't a study of Kirk being consumed by guilt and thus being unable to function. It was a question of whether he was greater than the burden he carried with him. One could say the same thing about "The Conscience Of The King."
And throughout the series the characters had moments when they questioned whether they were doing the right thing.
But "The White Iris" is all aboit proving Kirk had genuine feelings for certain women in his past and proving he wasn't a cad and felt genuine guilt and remorse over their deaths. That is the entire story to reconcile the character with more contemporary perspectives. But it is not a story the TOS writers would have written back in 1966-69 or 1969-70. They would have not seen the need to "fix" the character.
And "The White Iris" flies in the face of STC's stated intent to pick up where TOS left off as if it were still 1969. The story revisits characters the TOS writers wouldn't have bothered with and the story itself is not the kind of thing they would have thought of producing. But "The White Iris" is ideal fodder for TNG where more than once they dealt with Picard being heavily introspective.