Edward Barrett son of Michael and Ellen Rourke?

Hello to you all! I've been looking for a family line in particular, very elusive.Their surname is very common in the south of Ireland, but there are few in the midlands area. I was able to find some interesting things in a genealogy group, but I always have your expertise  to check it out, to see if these makes sense and can be correct.What I have is this:

Edward Barrett , my 2nd great grandfather married Mary HIggins in Toberclare on 1st of March of 1839. They had,as far as I know 7 children, being the first one named MIchael born in 1840 in the same parish

Trying to locate Edward's records, and being Michel his forst son, a friend located for me an Edward Barrett,born on march 4th in 1823, son of Michael Barrett and Ellen Rourke, in Roscommon, but my surprise was when we found a brother of Edward's, John Barrett born in 1821, same parents but in the baptism record says their residence is 40th Regt Foot,in Parish Templemore, Tipperary.  this friend of mine found a military record of Michael Barrett,that says:
"First name(s) Michael
Last name Barrett
Birth year 1787
Birth parish Dunfeeney
Birth town Killalla
Birth county Mayo
Birth country Ireland
Service number -
Regiment 40th Regt Of Foot
Year 1813
Attestation date 22 Oct 1813
Attestation age years 26
Discharge corps 40th Regt Of Foot
Document type Discharge
Archive reference WO 97
Series Wo 97 - Chelsea Pensioners British Army Service Records 1760-1913
Box 559
Box record number 53
Archive The National Archives
Country Ireland
Record set British Army Service Records
Category Military, armed forces & conflict
Subcategory Regimental & Service Records
Collections from Great Britain, UK Other
The photo of the record is attached. 
All I want to you to say, if I am in a good trail, and i fact this Michael could be Edward's father

PS: all the Griffiths and other documents points to the places my family were from

Thank you in advance