Find what names are missing in sheets

Hi,
I am using VLOOKUP to find values matching a user name. I need a way to check for mistakes if I miss a user name in my sheets. Let me explain the attached example to show what I mean:
Sheets JOB1, JOB2, JOB3: usernames and stats for each user name
Sheets 1, 2, 3: user names I need to input manually (A), list of jobs (B) and stats added with VLOOKUP (C)
Sheet MAIN:
- here I need your help to find what user name from JOB1 (A) is not entered in any of the 1, 2, 3 sheets and find what user name from JOB1 (A) is not entered in any of the 1, 2, 3 sheets but has stats (value) different form 0. (Same thing for all the JOB sheets)
Of course in the real workbook there are more jobs and more sheets (1-40).

I hope I managed to explain what I need. If not please ask.
Thank you for your time!

Some hints maybe? Where to start?

Hi,
I followed your advise and placed the data in the MAIN sheet. My method for taking data from the other sheets is copy - paste link for every cell . It is OK for this example as there are only 6 sheets, but the real file has many more sheets. If you have a better way to gather the data please tell me. If not I'll do it this way for all the cells .

To compare and tell what is missing for JOB1 I use: {=IF(AND(I3<>$E$3:$E$5),I3,"")} (if there is a better way please help, especially for JOB3 where I need to compare only the user name and not the whole cell)

How to get displayed in C3:C10 only the missing user names that have stats <>0?

Any help please!

I understand what you mean but it is not an option for me. I managed to make it work for me as I neded, but now I do not know how to display in C3:C10 only the missing user names that have stats <>0.