Question for more veteran lore-nerds. Considering the main 1000 marines are just the companies infantry units, not considering the detachments allowed to the various strike cruisers and battle barges for boarding defense/command, or the vehicle drivers and various additional techmarines assigned to the ships and vehicles, how many marines do you think would make up a typical, mostly-Codex compliant chapter of the Adeptus Astartes? And how many of those do you think would be techmarines?
There are no more than 1000 battle brothers in a codex compliant chapter, though generally there's a lot less, with the exception of techmarines, librarians, chaplains, and the chapter master all of whom occupy a position outside the the company command system. In general there is at least one techmarine and chaplain for any given company, under the authority of the Master of the Forge and High Chaplain. Apothecaries are part of the company the serve in as I understand it. The number of librarians varies highly between chapters due to different rates of psychic potential. dreadnoughts may also change the exact amount of marines in the chapter.
Ship bound marines are part of the 1000 marines, belonging to specific companies, usually the fourth or fifth in the case of ship and fortress garrisons as I recall, these companies are usually tasked with defending the Chapter's domain. Vehicle crews are part of the company to which their vehicle is assigned.
The tenth company can number anywhere between a hundred and several hundred neophytes/scouts. These individuals are not full fledged marines, though their sergeants and captain are. The scouts serve as a recruiting pool for the 9th company, progressing when a battle brother dies and they are deemed ready by their sergeant. The 9th in turn is a pool of recruits for the 8th, the 8th for the 7th so on and so forth.
Administration, logistics, support staff and other such roles are filled by chapter serfs. Such serfs are sometimes failed aspirants or simply indentured servants or servitors. These individuals do most of the basic work required by the marines, manning the majority of stations on their spacecraft, such as auspexes, engines and guns, though overall command usually belongs to an astartes captain or sergeant assigned to the ship. Gun turrets in the Chapter fortress are usually manned by serfs or servitors. Various human tech adepts are also usually assigned to the chapter to maintain parts of their fortress and aide in ship maintenance, though vehicle and wargear maintenance is generally restricted to the techmarines and their servitors.
The head of the Apothecarion is usually outside the company structure, serving as a senior officer at a similar rank to a captain, though with a primarily non-combat role. Some chapters have other command level staff outside the normal company structure.