Okay then, ban Lia Thomas because she's 6 ft tall, that's fair enough. Just apply it consistently.
The argument is whether a mediocre male will beat top women despite HRT. Height is an advantage that is not going be erased and will leave a male in the top 15% ahead of biological women in outside the top .1%.
Now whether that is a reason on its own to ban Trans participation is a different matter. But the claims that HRT somehow erases biological advantages in swimming for any given individual is baseless and absurd.
A biological male who is 5'5 and transitions will not raise those issues for the same reason a biological female who transitions to male will rarely raise them. Because sports is based on actual laws of physics, not a desire for a specific morality. And frankly as its a competition, it only matters insofar as it effects the competition.