The only reason you can leverage the program because it's well recognized. If you couldn't get a decent job and it's not well known then how would you leverage it. Look in Asia (Korea, Japan, China) LSE is extremely well known. I was talking to my client in Singapore and he was so proud that his nephew got into MSc Finance. Also this week I was interviewing at the biggest Accounting firm in China and their head HR didn't even know HEC (told them my gf will be going there for exchange). HEC is well known in Europe and top-tier BB and banks, but other than that, not many people know HEC. If you want a placement in Societe Generale, BNP or other french banks HEC is definitely the best option, since these banks recruit heavily from HEC. You can see on Linkedin, search HEC Paris and Hong Kong. Majority of those people are in French banks or the retail luxury industry.
But if you look on wallstreet oasis some people didn't even know HEC and that's a pretty huge IB and Finance community (North American and UK based). People are ignorant, if it's not related to them, they're not going to actively research about thing they don't care about. So it's only normal, that people in English speaking country will only know about NA and UK schools. OP wanted English countries, so it's better for an English school.
MSc Econ and other Econ, MSc Finance and some argue Msc Accounting and Finance, MSc. MiM & Strategy are its flagship programs. All of these cost over 20K. It's only reasonable to assume that their flagships have decent quality.
HEC is arguable better than LSE in Europe and it's a great top-tier school, but outside of Europe LSE is a lot better.
Sorry after the wall of text I realize I am not really answering the quality part. I honestly think the "quality" of most of these programs are around the same. Not just LSE and HEC, but every other European MSc Finance, other than LBS, but that's special (designed towards experience professional). You learn around the same type of things in class (DCF, binomial tree, black scholes, fin leverage and timing, etc..), regardless of class size; involvement is pretty much personality base (if you like to talk in class you do, if not you don't) and great profs. Some might be more case base, while others are more project base, but overall difference ain't going to be a huge, since most of the stuff you learn in class isn't super useful at your workplace, You aren't doing due diligence or working on pitch books (assuming ibanking) in class. That's why there are non-finance and accounting ppl in analyst roles for BB (since most skills are learnt hands on).