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So unlike the 41st / 42nd millenium era Adeptus Astartes Chapters according to Codex Astartes which are limited to thousand line-marines, the Ultramarines had 25 Chapters each 10000 strong. So my question here is, did these Chapter counts include also the supporting crew not counted in Codex Astartes Chapters into the thousand Asrtartes limit like HQ, Techmarines, Apotcherary, etc...?

That... just sounds like a typo or a misread somewhere, my understanding is that their Legion size was such they could split into a much greater number of Chapters than any other Legion... but those Chapters were still only 1000 Marines each (plus serfs, etc). Do you have a source?

Basically during GC/HH era an Ultramarines Chapter was composed of ten companies each a thousand line-Marines strong. So ten companies per Chapter means at least ten thousand line-marines per UM legion chapter. With there being 250000 Ultramarines, it means they had 25 Chapters.

What I am trying to get at is that if these numbers only include the amount of front line infantry Marines.
https://wh40k.lexicanum.com/wiki/Ultramarines

"
During the Great Crusade and Horus Heresy, the Ultramarines were a much larger Legion commanded by Roboute Guilliman. Beneath him were Chapter Masters who led approximately 10,000 warriors and a segment of the Legion fleet. Each Chapter was in turn divided into ten Companies of 1,000 under the command of a Captain.[50]"

The source for this is HH book five.

Yeah.... in HH era, "Chapter" was one of the terms used interchangeably with "Great Company", "Grand Company" and "Host" (amongst others) by the various legions as a thousands-to-tens-of-thousands strong formation.

Also - to answer the question - in Heresy era, there will be a lot less supporting personnel, because Legions used to have army, fleet and mechanicum personnel embedded or under their command a lot more. As an example, Hommed and Sarrin - the equivalents of a 40k Master of the Fleet for the ultramarines and world eaters respectively - are human naval officers, not astartes.