The emoji-scale 1-5, how exactly do you define that scale? Do you give feedback on a per-person basis or company wide? Say I have a team of 3 engineers, all wit

The emoji-scale 1-5, how exactly do you define that scale? Do you give feedback on a per-person basis or company wide? Say I have a team of 3 engineers, all with "Senior" title however I expect one to naturally outperform the other two. This quarter s/he's slacked a bit, maybe s/he's not as driven or it's something personal - but s/he's still performing just as well as the other two engineers who've both performed exceptionally well and I'm giving them both a 5. Do I give the engineer I expected to do better a 5? Or a 4? I mean I expected them to do better but I'm still really happy with their work.