Not gonna lie, I had the same thought a few times while watching GoT. He makes for a good "unknown" option, but I have a strong feeling they'll want to go with a bigger name for this one.
Came in to see if anyone had suggested Pascal yet, am not disappointed.
The thing is, sure, it's all guesswork as to what Marvel is thinking. But right at this moment, Pascal is as big a "name" as Chris Hemsworth was when he was cast as Thor. (Otherwise known at the time as "that guy from the first 10 minutes of Star Trek? Kirk's dad?")
(Mind you, I am not dissing that. Everyone said he killed in that scene. But he didn't look very Thor-ish in it, and maybe it's just the circles I run in, but I wasn't seeing anyone remembering the actor's name, all that much, at the time.)
Conversely, Pascal is coming off an entire season of GOT, which is a very high-profile show, and an awful lot of fan and critical reaction to the season has mentioned him as a highlight. He had way more than 10 minutes to capture audience attention, and he made every minute of it count. Everybody's talking about him.
Maybe I'm guessing wrong, but, it seems like it would be a very smart move for Marvel. He's NOT already an Oscar-winner (like Leto; a choice I also don't really love), he's not enough of a "name" yet to command a really high salary (I'd think). But coming off this GOT season he's got just enough of a profile to make it seem plausible. If I were Marvel, I'd look at the reactions to Pascal's performance in GOT, and I'd look at the internet reaction to Gwendoline Christie getting cast in Star Wars, and I'd think really hard about how much positive buzz this guy could generate right now.
And it's a great casting choice for avoiding the "yet another white guy?" issue, if anyone cares about that. (Not saying Marvel does, specifically, but if they were smart, they could generate a lot of positive coverage and interest by casting "the first Latino superhero".)
Also, he's old enough to make for a plausible Strange, but young enough to play the role for like the next 10 years. (Although I maintain that Strange ought to be a role where the actor ageing shouldn't be a big issue.)