Maitland's inclusion as the only uncapped player in the team had been widely expected but Grant's elevation, to the role of vice-captain along with a more obvious choice in Greig Laidlaw, was rather less so.
"I like what Ryan stands for," the caretaker coach explained. "I said yesterday what I like in captaincy and what I like in leaders and he probably falls into the deeds [rather than words] category and I quite like that. Looking at Scottish rugby history, props have been pretty successful captains in the past and he's a quiet guy, but when he talks people listen. I quite like that, too."
Peter Horne, who would certainly have been another to arms had he not shown the morale fibre to declare himself unfit for duty, meanwhile earned favourable mention in despatches.
"That was a great sign of maturity and he's a special lad, the fact that he made the call himself," Johnson observed. "He wanted to give it a crack and he made the call. It says a bit about the lad because it's an opportunity he would have loved to have."
The interim head coach and his principal assistant Dean Ryan, like Grant a former army man, had declared that they were looking for men of action and the selection reflects that.
Whether they can overcome the twin handicaps odds of recent form and poor historical results when they seek to storm their oldest enemy's fortress is another matter, but those they have chosen are up for the fight as their rookie confirmed. "It'll be a hell of an occasion. We haven't won there for 30 years and that's all the motivation you could need," said Maitland, who arrived at Glasgow Warriors just two months from Canterbury Crusaders.
Another significant inclusion was Dougie Hall, a 10-year veteran of Test rugby who will play his 40th match, yet make his first start for six years such has been Ross Ford's hold on the No.2 shirt.
"Dougie's form with Glasgow's been really good and Ross hasn't played for us for a substantial period of time. So it's a combination of the integrity of the selection and also understanding for Ross that it's a good place for him to start again off the bench," Johnson said.
It is a major overhaul following the humiliation against Tonga at the end of the autumn Tests with only seven players retaining their places and Matt Scott only doing so because of Horne's injury.
Laidlaw (to scrum-half) and Sean Lamont (to outside centre) shift positions while the others brought in along with Maitland, Hall and Grant are Ruaridh Jackson, Jim Hamilton and John Beattie, who returns after a two-year absence.
"I remember watching [Beattie] years ago at Aberavon playing for Scotland under-19s and I said then he was a precocious talent," said Johnson. "To hold down a slot with a very strong club in France in a very strong competition says a bit about his form and we've rewarded that. He can do things as well that others can't."