https://www.themoviedb.org/bible/tv/59f73eb49251416e71000022

It is completely normal for regular cast members to be missing from one or a few episodes of a season.

They all appear in more than half of a season, so it's all subjective. One could say that 5-6 episodes out of 8 are "most episodes of a season" because it's more than a half, and the bible doesn't give the exact definition of the "most". John Bradley and Zine Tseng appeared only in 4 episodes (half), so they were removed from the regulars.

Rosalind Chao, Marlo Kelly, Sea Shimooka, Alex Sharp, Saamer Usmani are apparently credited as series regulars in the episodes they appear in and they appear in most of the season so they can stay in the Regular Cast section.

Jonathan Pryce, whose character was killed in episode 5 and thus is absent and uncredited in episodes 6, 7 and 8.

Since his character was killed, Jonathan Pryce has been removed from the Regular Cast section. You mention he doesn't appear in episodes 6-8 so I added him to episodes 1-5. If he does not appear in one (or more) of these episodes, please remove him from said episode(s).

Since his character was killed, Jonathan Pryce has been removed

I wonder, how does the fact that the character has been killed have anything to do with him being in a regular cast or not? Someone might be killed in the first episode and return in the flashbacks for the rest of the season, for example. What matters is that he appeared in most of the episodes and was credited as a regular in each of those episodes, everything else is irrelevant. Alex Sharp's character also died, and wasn't credited after that, so what, remove him as well?