1) I can tolerate him/her having less shifts that the other employees, but his/her arrival at work is also late.
2) Having less shifts is tolerable, but he/she is also late for work.
1) & 2) " 他の人よりシフトが少ないの許せるけど出勤時間も遅い" という意味です.
I can tolerate him/her :(彼/彼女)を許される / Is tolerable : 許される
having less shifts that the other employees:他の従業員よりシフトが少ないの
but his/her arrival at work is also late / but he/she is also late for work:けど出勤時間も遅い