Rod

Hi. I think you need some input from a specialist n German troops, but for what it’s worth – given you have no other takers:

AFAIK, the Brunswick Oels did indeed have 12 companies, but only 3 of them were designated as independent companies – the nine companies (+ HQ) operated as a (formed) light infantry battalion.
See Oman, Wellingtons’ army which provides some information to support your assumptions about the company attached to the fusilier brigade (but not, frustratingly, definitive evidence of them at Albuera)
The light battalion (9 + HQ) appears to have originally been assigned to 4th division, switched to the light division (but there were – I think – some concerns about their use in outpost duties) and then switched once more to the newly forming 7th
So in 1811, there were 3 jaeger companies, namely: 1 in 4th (division) and 2 in 5th (division) helping to form the independent light battalions in these two divisions

See http://www.elkridgeorchard.com/IR92/history.htm

Hope this helps somewhat and is not too erroneous!

A