Which videos do you recommend from the quantitative strategy section

So I have gone through most of the concept building videos from the quant section and was thinking about working on my strategy. However, in the quantitative strategy section there are at least 3 different series (quant strategy, quant toolkit and improve your skill) which seemed to be going over the same skills (at least from the look of it).

Which series in particular would you recommend as being good enough to cover all the skills?