On Australian I find it the hardest to comprehend at 2x speed, especially the bogan/yobbo flavour. Have to really pay attention for that one.
so scots are to english what chileans are to spanish?
That gets fun.
In general most of the non English languages* are spoken as a second language at best (maybe learned in school if you grow up there but forgotten 5 minutes after the last exam), and then mostly to amuse tourists, pretending to only speak it to annoy visitors in pubs (especially if they are English, though sometimes American), in the Republic of Ireland then the Irish language it has recognised status but so few speak it that most do it to annoy police (being comprised from the general public they don't speak it either so are duty bound to get someone that does), get shorter lines in public services (again duty bound so will usually open a separate window) and so forth.
*most usually think English, Welsh, Irish and Scottish Gaelic but there are also Cornish (almost went extinct but earlier in history was the source of several rebellions), Manx, tweaks in the various islands and territories still associated with the UK (Gibraltar is an odd one for this if you want one with a Spanish twist, though it is more borrowed words than accent).
To that end we are then back to accents rather than language for Scottish, though with any amount of history thrown in as well (to avoid the various pieces of history here is about like avoiding the War of the Confederation in doing South American history).
That said unless a Scottish person is drunk, has one of the harsher sub accents (Edinburgh, highlands, Glasgow and Aberdeen are as distinct as anything else once you know what to look for, for my money Glasgow housing estates, or housing scheme if we are to use the Scottish term, probably produces the harshest, which is fairly common anyway -- go to the poorer and/or rural parts of any town/county and you will get the thickest, possibly in both senses of the term), flustered and is making no effort to hold back then I would give you way better odds (as a mostly learned by listening to games, films and TV type) on being able to understand them than some of the various efforts from England
Skip to about 7:20
Skip to about 2:20
Technically something of a comedy/satire but
or the same but more serious (also not a bad take on informal RP/BBC accent to begin with for those were not quite sure what was meant earlier)
There are plenty more than just those that get hard if you have not grown up there or otherwise heard them a fair bit ones too. Some might even accuse me of taking it easy on you by only selecting those. It is however why those from the UK (and Ireland) generally laugh when someone says British accent. A lot of those were old people talking old ways even when they were being filmed decades ago and things generally have all softened somewhat, however you still find pockets (I spend a fair bit of time in East Anglia and found people in their 20s that sound like the video above when in the wilds there).