Yea, it's complicated. The network/web security at my company is (let's just say) high. Here's my situation:

Background:
2015 SP2 is currently deployed to users via an Admin Image that I didn't create. I'm the CAD Admin for our company. I'm unable to use the installation manager as it reaches out to "who-knows-where" storage sites that are blocked from me. I have a 2016 SP2 disc from our VAR. I'm wanting to update to 2016 SP3. I can download the individual files for upgrading SP2 to SP3. I'm new to creating Admin images. I attended SWW 15 and 16 where I attended some classes for Admin Images.

Question:

Can I create an Admin image using the 2016 SP2 disc I have, then select the SP3 update to be done at the same time? I know you can attach (what I think is) only a single file, but can you have an image for SP2 add-in the SP3 update too - all at once? I don't think so, but I'm asking. A coworker thinks it's possible. Suggestions?