I personally prefer using only one Trading strategy, During my early trading days i went through so much strategies from one to another to choose the one that best suit my style. After a while i was able to pick one don't think i will ever use another strategy apart from mine to avoid complications.
In my own case, I'd prefer making use of a single strategy but when am using that for a long time and over this period without having a result to back it up then i try to switch or change to another maybe i could use another approach to get a better experience with my trading, this is how I've been always staying with these kind of situation because i like holding onto something but not when am not having good results from it, then i try to refrain myself for another option.
if you are still in the learning stage it is better to use one strategy, because we will analyze the progress of the development of our trading system first, until we achieve the goal of getting consistent profits in trading. after feeling that you have mastered one trading system, then we can develop another trading system, it aims to approach methods from several existing trading systems, so that we know the advantages and disadvantages of each system used