As we all know, Codex Chapters consist of a (nominal) 1000 Warriors consisting of ten Companies of 100 Marines each. Add to that the Librarians, Chaplains, Command Squads and so on and that number can grow quite a bit.
As I have a full Second Company I decided that additional elements such as Land Speeders, Bikes and others would be crewed by Marines from the Reserve Companies.
With that in mind, the bike mounted Command Squad and Land Speeder Squadron shown below are from the 6th and 7th Companies respectively. The Codex indicates that the 6th is equipped with bikes and the 7th Land Speeders. To that end, I need to change the transfer to a Tactical arrow on the Speeders.
This means of course that I can throw in a full 2nd Company plus support without some pedant (because they do exist) pointing out that "There is only 100 per Company". If I purchase any Centurions in the future, they will have 8th (Assault) or 9th (Devastator) colourings.
The Chaplain is the 6th Company's and as with all 2nd Ed character models, the relative simplicity beats all the modern faff!