Who are the others?

[Once]

We know the envoy is Harys Swift, one of the guards was Raff, and the others?

There were four guards; big, hard-looking men in ringmail, with heavy Westerosi longswords sheathed at their hips. Their crimson cloaks were bordered in whorls of gold, and golden lions with red garnet eyes clasped each cloak at the shoulder. When Mercy glanced at the faces beneath the gilded, lion-crested helm, her belly gave a quiver.

Guard #2

He was an older man, big-bellied and grizzled.

But also big and hard looking like the rest.Worked with Tywin when he was Hand. Arya wasn't interested in him though. Is he Shitmouth? He was one of Gregor's men who fits the description and did not end up in her list because he was nicer than the rest.

If I understood this part well, he worked with Clegane so it might makes sense:

“What, are you mad? You think he notices the likes of us? Bloody bugger don’t even get our names right half the time. Maybe it was different with Clegane.”

“Ser wasn’t one for mummer shows and fancy whores. When Ser wanted a woman he took one, but sometimes he’d let us have her, after. I wouldn’t mind having a taste of that Black Pearl. You think she’s pink between her legs?”

Of course, all depends on how that part is interpreted.

We have no info of the others, that's all there was. Any ideas?

[Formerly Tetrarch42]

It's really hard to say. I don't think it could be Shitmouth because he would have a familiarity with Gregor. Also Shitmouth is tucked away in the Riverlands.

He's certainly much more respectable and... un-psychotic, when compared to Raff.