Williams, who has primarily worked as a pundit since , on Monday along with former Swansea boss Alan Sheehan.
It will be the 42-year-old Uefa A Licence holder's first senior coaching job and comes after and exited the Wales set-up.
Vokes, a member of the Wales squad that reached the Euro 2016 semi-final with Williams as captain, feels his former team-mate will be an asset.
"I was a bit shocked because I'd seen the success Ash has had in the media world - you see him on a Saturday night if you turn on Match of the Day," Vokes told BBC Radio Wales.
"It's a good recruitment by Bellamy because I played underneath Ash as a captain, and he was a great leader in the dressing room and led by example in the way he conducted himself on and off the pitch.
"He can be someone who speaks from experience and [will] go into that dressing room and immediately command respect.
"It will be great for the younger lads who have seen him play over the years. He'll bring all the experience he's got into that set-up.
"The first camp - away at Portugal and Denmark in the top end of the Nations League - he has played in those environments.
"He will be able to speak to the lads that are going out in those environments because he led by example, and led in the trenches many times. "
Williams completed his coaching badges under the Football Association of Wales' umbrella alongside Vokes, and will get his first taste in the dugout with a trip to Portugal on Thursday, September 24.
