Transfermarkt is unfortunately not always a reliable source for birth dates. I'm not certain on the other websites you have used here, however, I know that some of the players you have mentioned have the correct DOBs in game. Often an incorrect DOB from a website like Transfermarkt is spread over several others.
Only recently, I had to update Reuben McAllister's DOB on his Wikipedia and Transfermarkt page because it was incorrect. Confirmed on his UEFA page and by Kelty Hearts as 10.06.2006, (Reuben McAllister | UEFA Europa Conference League 2023/24 | UEFA.com), whereas, most places like Transfermarkt had it, or previously stated it as being 15.05.2006.
An example - Jay Cantley is 02.09.2002 as seen referenced by his previous club on X, however, Transfermarkt is showing something different.
There is a few DOBs on your list I have confirmed with clubs or the players themselves, personally, so I know that they are correct.