Soviet Guard Army?

[mboat]

I play the 41 campaign ,use Soviet.
After 1941's winter, I get some Soviet Guards Unit, including Inf Div, Cavalry Div, Artillery, Tank Brigade or Tank Regiment, ect.
1. But Why did the Tank Corps and Mechanized Corps not become Guards Unit? The experience of these Corps had reached over 90. Even the Tank Brigades or Regiments under these Corps had already been Guards Unit.
2. I found some Soviet Guards Army Unit, such as "1st Guards Army"(in Campaign 42) and "5th Guards Tank Army"(in Campaign 43). Can I use these Guard Army Unit if play from 1941?

[RickyB]

Not sure as to number 1. I know there are limits as to how many units convert at the division level, but I have no idea how or if corps might.

For number 2, these units you see in the other scenarios are there strictly for those scenarios, each one is independent and there are a number of specially named units that are not present in the main campaign either because the formation was temporary or other units are considered more important, or just by pure luck.