The one attribute the teenager lacks is the self-confidence that England internationals Delon and Steffon have in bucketloads.
And for the time being Guy is purely focussed on emulating Irish youngsters Tom Homer and Jonathan Joseph rather than following in his brother's footsteps for now.
He said: "It (being an Armitage) makes it a lot harder given what they have achieved.
"They are top class players so it is ridiculous for me to be compared to them. It can be a bit overwhelming at times.
"The main thing is for me to set short-term goals for which to work towards and ignore everything else is that is said.
"I am not naturally a loud person and that's been the main focus for me during the A-League games to become more assertive.
"I am a lot more laidback than Delon and Steffon - I don't talk unless I need to.
"The academy coaches have just told me to play with confidence and make sure I enjoy it. I know the coaches would not have started me unless they have confidence in me.
"If I had my first team chance anytime before now I would have been happy but when I looked at the fixture list at the start of the season this was always been my target.
"Tom Homer did it last season when he was given a chance and Jonathan Joseph has really stepped up this season so they are the inspiration for me."
Rugby mad father Colin made the 500-mile round trip from the family home in Devon to watch Guy make his Exiles debut against Sale Sharks in the LV= Cup earlier in the season as he became the fourth Armitage - after Delon, Steffon and fellow centre Bevon to cut his teeth in professional rugby.
There could be five with big things expected of prop Joel - the 15-year-old who will start at Wellington next year.
But Guy's introduction to the oval-ball game when the family was growing up in the south of France was far from a happy one.
He said: "My dad put a rugby ball in my hand for my first training session when I was four and I remember crying my eyes out.
"We were there watching Steffon play at Nice and part of the pitch was roped off for an under-sixes game. He asked me if I wanted to join in, I think I said no and I ended up getting dragged across by him and the coach.
"My mum has got all the co-ordination so that is where that came from but it is my dad who gave us the love of rugby.
"It is very hard for us all to get together as a family because we all have so many commitments.
"But every summer we have one day where we have a family barbeque where everyone comes together.
"We don't really talk about rugby but we generally have a table tennis competition.
"I am pretty handy but Steffon is still the best. Delon likes to think he is but he is probably second and I am third but Steffon wipes the floor with us."