1 primary sidearm
2 ???
3 ankle gun
Just going from how you described the dude, and his past experience.
1. Glock 17
2. H&K MP5
3. Sig P365
1 primary sidearm
2 ???
3 ankle gun
Ok. So was he a Special Agent or a contractor? If a Special Agent, then he would have to have a college degree. Then he would've spent several months in training, followed by a year or two in a field office in the US. While he might get some protection assignments, either for visiting dignitaries or overseas on short deployments, most of his time would be spent investigating things like visa and passport fraud.
As a contractor, he would've spent his entire time on protection details/security assignments. His miltary background would've been sufficient to land a contractor gig, even without a degree. DSS used a lot of security contractors in the last 20 years.
Not saying you have to use this information. After all, it is fiction. But if you're striving for some accuracy in this character's background, I think it's good to have. And this info is out on the Interwebs if you want to research it yourself.
Just my opinion.
As a writer, I see your worst problem right away. You don't know your character nearly well enough. And you may not know guns enough.
YOU have to decide on his income, sophistication, clients, etc. I think you need a private eye. Bodyguard alone is too limiting in scope.
Look inside his personality. Look at his home. Describe it. Make the reader see it. YOU must know him. What does he drive? Does he like coffee? Who does he date?
Read books that define characters well and make you feel that you know them. David Lindsey is a superb wordsmith. Read his books like, A Cold Mind, Spiral, Mercy, Requiem For a Glass Heart.
Try writing fan fiction on FanFiction.net. Select a show you know and see if you can even make the known TV characters seem real to fans.
He should own at least a concealment gun and a full size pistol. Maybe a 5.56 mm rifle.
I don't know this man or if he hates okra or peaches. I don't know his real income or gun knowledge.
Personally, I wouldn't make him too poor. Maybe not too rich, either.
Take a creative writing class at a junior college and read similar fiction heavily. DO NOT make him your egotistic self. This gets a writer laughed at as a Marty Stu. You'd better be good at dialogue, too, and in character!
You aren't ready to select his guns until you've thoroughly created him, friends, likely assignments, clients, city, etc.
Who carries a Glock 26 in a ankle holster ?
Just as a lark, I'm writing a short story where the 'hero' is a bodyguard. I've given the hero a back story of service in the USMC Force Recon with tours in the sandbox. Since mustering out has 2 years in Diplomatic Protection Service before going into private security. He's struggling a little financially. Would he still own 3 guns?
What three guns would he own? I have ideas but I don't trust my own bias.
1 primary sidearm
2 ???
3 ankle gun
If you can see an obvious mistake in my thinking, please tell me so I can fix it.
My character's main assignment is executive protection and has a business suit dress code. He has a pocket clip-on knife which I have yet to define.
Honestly, I didn't envision a long or longer gun but now can't envision him without an AR platform firearm. "Every Marine a rifleman." So this would be in addition to the three pistols I originally envisioned but didn't specify.
I did, for one. My BUG to my 17 or 19 as armed security or LEO duty.
I still think exec protection, which I did for over a decade, is too limiting a field, unless your hero is maybe US Secret Service, foiling a plot. Maybe he could be a DSS supervisor foiling a plot to kill an ambassador?
But those agents aren't your proposed hero.