Do we know of any language that allows /r/ + /h/ + /l/? If I recall correctly, I believe Ancient Greek had /r/ + /h/ (or /x/?), hence 'rh'. And there was /h/ + /l/ in Old Norse. At any rate, I've never heard of a language that allows /r/ + /h/ + /l/ in word-initial position. I haven't a clue what that apostrophe in R'hllor stands for, but I don't reckon it's a glottal stop. I mean, /r/ + /ʔ/ + /h/ + /l/ = LOL. Do any Slavic languages allow this consonant cluster? I know Czech and Polish have 'ch' [x] + 'l', and /l/ or /r/ can be the nucleus of a syllable...
Anyways, I can almost pronounce "R'hllor", but it just sounds off and unnatural. So I guess you could say that maybe it's phonetically realizable but I'm more interested in knowing whether there's a language that does, in fact, allow this sound sequence. Would the trill being voiceless help? I've no clue how to make that, but apparently Icelandic and Welsh have a voiceless /r/, so there's that, lol.