"The first guy is a man with no name, who is up to no good." That would be the Assassin. Also known to GAME OF THRONES readers as "the guy with the dagger."
The second guy is a man with no name, who is up to no good. We're talking Wineseller here.
"The first guy has been a guard and a garda, he's slept with beasts and eaten a girl, he knows that anything that can go wrong will go wrong, he's seen sleeping dogs and flying saucers, and met Kavalier and Clay's greatest creation (or did he)?"
He's LALOR RODDY.
Roddy has appeared in GUARDS and played a garda in SUMMER OF THE FLYING SAUCERS. He's acted in AS THE BEAST SLEEPS and BOY EATS GIRL and MURPHY'S LAW and THE ESCAPIST (not actually based on Michael Chabon's fine novel, alas).
"The second guy is not simple and he's not high, but he's been to the beach and crossed the Mersey, seen his share of doctors, and once went down in flames. Oh, the humanity, the humanity."
He's SIMON (not simple) LOWE (not high).
http://www.simonlowe.net/index.html Lowe has been seen in MERSEY BEAT, in BEACH BOYS, appeared in twenty episodes of DOCTORS, and went down with the Hindenberg.
As for the second pair...
"The first guy loves goats... " That's Shagga, son of Dolf, who likes to feed the goats with the manhoods of those who vex him. "Is it rabbit or rarebit? The first guy might know." Is it Welsh rabbit or Welsh rarebit? No matter, the actor's Welsh. "The first guy has been a nobleman, a moron, and a hog." He was Mr. Hogg in MASTER AND COMMANDER, played in MORONS FROM OUTER SPACE, and appeared as Lord Brandon in THE OTHER BOLEYN GIRL. "The first guy has been every flavor of cop." Constable, inspector, deputy, chief constable, chief inspector, sergeant, you name it, he's played it.
Shagga will be played by MARK LEWIS JONES.
"... the second likes his meat tough... " Who else but Greatjon Umber?
The Greatjon will be played by CLIVE MANTLE.
It was Clive who conquered India... but not THIS Clive, to be sure. "The guy who had more dingers than anyone but the guys who liked the juice, well, the second guy isn't that guy, or even the guy who chased that guy all summer." That's a clue for baseball fans. The guy with the dingers is Roger Maris, whose single season home-run record has been surpassed only by juiced-up cheaters. But the guy who chased him all that summer was Mickey Mantle. "The second guy holds a record: the biggest little guy." Mantle played Little John in ROBIN OF SHERWOOD, and is the tallest actor ever to play that role. "The king of the deep knocked the second guy topsy turvy." Mantle was in THE POSEIDON ADVENTURE, about an ocean liner knocked upside down.
And here's a freebie for you, a casting I gave no hints about. SUSIE KELLY has been cast in the role of the innkeeper MASHA HEDDLE.
Those were likely the last round of clues from me for a good long while. On Monday we will be heading down to Melbourne for worldcon, and I don't expect to be on line much, if at all. Casting continues, yes. There are still parts to be filled: Ser Ilyn Payne, Prince Tommen, Princess Myrcella, Rickon Stark, Mirri Maz Duur, and more. But I'm not sure I'll even know when those are filled, and I'm pretty certain I won't have time to hint. So you're on your own for a month, boys and girls!