Ben,

There are some Portuguese contributors to this site more knowledgeable than I and who may be willing to assist with quite specific queries you might have. João Centeno has researched and written books on the Portuguese army in the Peninsula. João Centeno, Moisés Gaudêncio and Jorge Quinta Nova have made regular contributions to this site in the past - are active researchers and regularly post very informative blogs.

I think I'm right in assuming that there are three potential candidates from the nine British officers listed as serving with No. 5 Caçadores in Challis (on this site). For more detail though you require Ordens do dia.

William Stewart (Lt. Col. No. 5 Caçadores, Mar ? '10 – not fully legible for me in the Challis cards) was only in theatre and in Portuguese service for a relatively short time Mar to Oct '10. I’m still looking for more details on his commission.

Whilst searching I found the entry for the commission of Henry Perry as Capt. No. 5 Caçadores, which is reported in Ordens, 1810, p. 66. Quartel-General de Coimbra, 24 de Março de 1810 as follows: “Cap. de terceira companhia de Batalhão de Caçadores No. 5 o Ten. Henrique Perry.”

Michael McCreagh
Bt. Major Portuguese Army (27 Apr '09) and Bt. Lt. Col (PA) 3 Oct '11.
However, he's also listed as Lt. Col. No. 5 Caçadores 3 Nov '10 and Col. Regt. No. 3, Infanteria (10 July '13). Challis

Found this in Ordens.

Ordens, 1810, pp. 193-4
Quartel-General de Sapataria, 13 de Novembro de 1810….
Por decreto de 3 de Novembro de 1810…
“Tenente Coronel do Batalhão de Caçadores No. 5, o [antigo] Tenente Coronel do Regimento de Infantaria No. 7, Miguel Mc Creag.”
NB [antigo] my edit, and the c in Mc is superscript, but this site doesn't support the font

John Humphrey Edward Hill.
Major No. 5 Caçadores (3 Aug '11), subsequently Bt. Lt. Col. (21 Sep '13).
Lt. Col. Regt. No. 4, Infanteria (15 Nov '13). Challis

Ordens, 1811, p. 167
Quartel-General de Cintra, 9 de Setembro de 1811….
Por decreto de 30 de Agosto de 1811…
“Major do Batalhão de Caçadores No. 5, o Capitão Hill.”
My emphasis

Collecção das Ordens do Dia, do Illustrissimo e Excellentissimo Senhor Guilherme Carr Beresford

Hope this is of help.
Best wishes
A