Change groups of files with incremental numbering?

[DocBean]

I'm trying to create a cinematic universe for Stargate. The requirements for that is that the files should be renamed in a special format, e.g.

SGU900-Stargate Universe S01E01.mkv
SGU901-Stargate Universe S01E03.mkv
SGU902-Stargate Universe S01E04.mkv
SGU903-Stargate Universe S01E05.mkv

It needs to start with SGU and the numbers incremental. The files on disk are currently named

Stargate Universe - S01E01 - Air (1).mkv
Stargate Universe - S01E01 - Air (1).nfo
Stargate Universe - S01E01 - Air (1)-thumb.jpg

So Stargate Universe needs to replaced with SGU and incremental numbers e.g. 900, 910, 920, so it is SGU900, SGU910, SGU920, etc. There are 3 files in each group; *.mkv, *.nfo and *.jpg, and each group should have the same filename;

SGU900-Stargate Universe S01E01 - Air (1).mkv
SGU900-Stargate Universe S01E01 - Air (1).nfo
SGU900-Stargate Universe S01E01 - Air (1)-thumb.jpg

Can groups be renamed, or do I have to select all *.mkv, rename them, and repeat for *.nfo and *.jpg