I know that sales and trading involves both type of products. What I tried to say is that imperial is more focused on quantitative aspects of trading, modeling, quant guys in C++ hedging the respective portfolios, looking for patterns to develop algorithmic trades, etc.
On the other hand you have "discretionary" traders and sales (brokers, financial advisers, etc). These guys knows a lot of finance and economics but they are not engaged in daily financial modeling or doing rocket science functions. They work more with customers and take an approach more holistic when trading (technical analysis, fundamental analysis, etc)
Every finance degree has derivatives and cash products related courses, I am just an Engineer majored in Finance and I had these courses.
What I said was, for what I have heard, that Imperial Msc Fin. is a better place to go if you want to make a career in a more quantitative role and LSE Msc Fin. would be better for non quants wannabe.
Now if the OP is looking to be a quant, he should look at Ms Financial Engineering, Financial Mathematics, or even the Msc Finance and Economics from LSE, which is much more quantitative than its Msc. in Finance.
Here are the requirements of both programmes. Take a look at what they ask in terms of quantitative background.
LSE: "Admission to the programme is very competitive. In previous years, the majority of students accepted into the programme have obtained first class degrees or the equivalent. The mathematics used in the programme includes basic calculus and statistics, so applicants are also required to have studied a minimum of A level Mathematics (or its equivalent). Prior work experience is not a pre-requisite for entry into the programme, but can be considered an advantage."
IMPERIAL: "A First or Upper Second Class honours degree (or international equivalent), from a recognised university, in a highly quantitative discipline such as mathematics, engineering, science or economics."
Regards