They are both entering 6th year because they each redshirted 2019 and because of Covid. It seems to me Cook definitely only has 1 year left, while CJ Clark COULD apply for a medical year because of a season ending injury in 2021.
@TheOriginalCane could look at his bio and give a better answer than me.
C.J. Clark (5) DT - 2022 SEASON: • Starting defensive end in the last five games of the season - he has also played nose during his career. • Had a monster g...
gopack.com
OK, from available data:
Marley Cook
2019 - played in 4 games, redshirted
2020 - played in 9 games, but COVID year
2021 - played in 11 games, "super-freshman" year
2022 - played in 13 games, "super-sophomore" year
2023 - played in 12 games, "super-junior" year
---Should have ONE YEAR to play one year, unless he was injured in 2024 and qualified for a medical redshirt
CJ Clark
2019 - played in 2 games, redshirted, had off-season surgery but does not appear to fulfill the medical redshirt requirements
2020 - played in 12 games, but COVID year
2021 - played in 3 games, but suffered season-ending injury, SHOULD qualify for a medical redshirt, "super-freshman" year
2022 - played in 13 games, "super-sophomore" year
2023 - played in 12 games, "super-junior" year
---Should have TWO YEARS to play two years, assuming he has applied for (or will apply for) the medical redshirt year
Essentially, nearly identical resumes, except for CJ Clark's injury in 2021.