You can remove KPMG, Deloitte and PwC from that list, they don't like high-schoolers anymore
You've missed plenty, opportunities are literally infinite, I can provide you with nearly everyone I've applied to/know that have Cadetships for this year, I'm not sure about next year though. Side note:
I don't recommend Boroughs the slightest bit, the most boring people and old-school you'll ever meet.
Did you meet the cadets? i think there's two cadets (maybe one now) there that are fairly active here
That 30 quote for EY is abit big(as mentioned by someone else), I think it was more relevant back in my year and maybe the year before mine when all the big 4 were doing cadetships and it was a pretty big thing, i remember my year, EY took around maybe 20 altogether?
Most of the big 4 scaled these back to first year university students i reckon because a lot people usually are very 50/50 on which degree/path to take.
E.g someone gets a Cadetship in June/July for example and accepts it, they do their HSC exams etc... then nearing November/December or when they get their HSC marks for example they really start to think about their degree, a lot of people might get like 99.65 or whatever which allows them to do law that they wanted to do(this is one of the more common situations of why people leave), so now for example, the person either risks resigning to do law, they do law anyway and hide the fact they're doing it by only doing commerce units and then quitting, or they do Commerce cause of Cadetship pressure, and then realise 1-2 years later they really should've done law, so they quit and pick up law as a degree.( you can switch law for any other degree in the context)
I can tell you other situations which happened every year, and i think its usually just easier for them to recruit first year cause they have people applying who already decided on a Commerce degree, so they have proved that little bit of extra dedication for example, and the fact that these firms have connections with societies, it makes it easier for them to advertise to a wide audience and get more candidates that don't usually think of things like this during HSC (where focus is on study more then anything).
That's just my take on it.
I should mention even though I said all the above, most cadets will actually stay for a decent amount of time honestly, its only a few who would do something like the above, but it does happen and it does add to the bottom line expenses in the end for training etc.., it takes some time for the firm to actually get a positive return on cadets being hired, so the more risk they can eliminate with hires going rogue the better for them I guess.
UBS one sounds about right actually, they did a major intake in 2014 and 2015(took like 12-14~ around then), but scaled back the 2016 applications, not sure about 2017 yet, haven't spoken to my bud yet.
Major Mid-tiers will have a decent amount of applicants actually, BDO, GT etc.. would have around maybe 300-400 applicants still, whilst the much smaller mid-tiers or ones that don't advertise would have around 100 as mentioned, so that sounds about right.