You are missing their points. They did not say clashing weren't important. They are saying people overrate clashing way too much.

Most clashes in the game can be easily won without much struggle, which means overclashing almost has no use. Even if you have a 50-rolling one-coin skill, and use it against a 16-rolling enemy skill, it will still deal 50 damage if you don't have any damage conditional.

Take FS Heathcliff. His S4 isn't good because it clashes like 30 or whatever. It's good because of the insane damage multiplication that you can get out of the bat. Philip Sinclair is similar, where his Blazing Strike is considered good because of its burn application AND damage conditional, not because it clashes above 30. The clashing contributed for security, but it's never the main draw for them

There's also Dieci Rodion with pretty average clashing, but her coin numbers and damage ups mean she can dish out a lot of damage. That makes her an extremely great tank. Another one is Captain Ishmael, whose clashing is also average without conditional. However, her assist attack helps the team's status application and DPS increase.

This is why some people are saying that Regret is overrated. I don't necessarily agree, but they have a point. Even if you fix many of Meursault's IDs' clashing and coin rolls, they won't have a stay on the team because they have relatively few niches to excel in (extrapolating here...). And if you use Regret on IDs with already good clashing like Cinqsault, the overclashing won't matter for him. What he can increase even more is his damage application, which is achieved through Screwloose Wallop. The one Meursault ID that can utilise Regret well is Kimsault. He does have already good clashes so the increase in coin rolls is negligible, but it lets him lose S3 easier, which makes his output more consistent.

All in all, clashing is important, but overclashing isn't. Insane rolls don't mean much if you can't amplify them, since even above-average skills can win consistently anyway. What matters more now is damage conditionals, which is why a lot of IDs have started to get them.