Current issues with my employers

I'm having a bit of an issue right now.  I raised another topic about my appraisal not long ago, but now this is about me and my brother.  My brother started with my company about a month ago after he wasn't getting challenged at his previous company.  He found he wasn't climbing the career ladder after 4 years so he's doing the same job but just with a different company.

But, my and my brother both have Asperger's.  Being male it's seems to be more prominent in him.  We both take our diagnosis differently.  He doesn't seem to be able to accept it and continues to try and be 'normal', where I am raising money for the NAS and trying to get more support and awareness in the area and accept myself for who I am.  We are in positions at work where we go to different oil companies and provide IT support when they need someone temporarily.  He was going to be stationed for quite some time at one particular company but they requested his removal and asked for someone else, so he's gone to a different company to help out now.

The problem was he got complaints.  Told he was being too brash, too blunt, not mixing in well with the staff, but when he was given work he did a really good job of it and is smart.  It's now ruined his confidence because he feels he needs to be really sociable to get anywhere in life.  I've tried telling him that people will just have to accept him for who he is, and I can see what a great guy he is, but socialising just fills him with dread and he's then so hard on himself.  We have the same line manager so when they were discussing the complaints our line manager mentioned that these complaints were probably from him having Asperger's.  I was friends with my line manager before starting work with the company so I would've told him then about my family problems, but now my brother is upset because our line manager knows about the autism and he sees it as a weakness.  He thinks he will not make it anywhere in life with this condition and that everything that is important in the world involves being good at socialising.

I've been very independent from a young age.  When I was about 2 years old I would help my Mum out by bringing nappies for him when he was getting changed and always looked out for him, so I feel I can deal with things a lot better.  I'm not saying I'm perfect, living on the autism spectrum is not easy and I salute everyone who does and/or has family/friends on the spectrum.  I have my bad days too but I have a strong independence that keeps me going.  I wish I could give some of that to my brother.  I want to show him he is an incredible person, but I don't know how.

I am going to try and meet up with my line manager as he visits my site on Thursday. I really want to bring this up with him because it's really unfair that we both seem to get scrutinised for just being who we are.  I've had all sort of doctor help the majority of my life, from speech therapy to physiotherapy to CBT to psychiatrists.  I've worked very hard to become the person I am today and I've got to that point where if you can't accept me for who I am then that is your problem, not mine.  But, my brother does not have that attitude (maybe a good thing as it gets me in trouble sometimes).  

I'm basically asking for help on how to bring up my concerns with my manager without being my usual 'brash' self, as I want to try and get a get my point across that once me and my brother are comfortable in a situation then we're very easy to get along with.  It's just with the moving about and meeting new people that's causing problems.  We are very intelligent, hard working, honest people, but all that is blinded by socialsing.  Everyone has weaknesses, but because socialising and speech is ours then people don't want to look past that.  Is there any information I can bring to this meeting that might help?  Also, is there anything I can do to help my brother's confidence with this?  We don't need to keep everyone happy, I know that's impossible, but I want to help him feel OK with being him.  It may not be possible, but I'm willing to try anything