O.K. so I risked opening the link.
I do not know if others will agree with me, but I thought that the video wasn't as helpful as it might be.
Sets are something that a lot of players have trouble with, and I suspect many players will leave the video being not much the wiser about what to do.
I would suggest that the explanation be redone.
There is need for a script that is followed logically,without ad libbing and mumbling some garbled explanation when something that was to be demonstrated doesnt work, or isnt avaialble, or doesnt show.
Unfortunately there is no tutorial for sets, but this is the link to official plarium videos and how they are professionally done.
I appreciate that English might not be your first language,and English has some peculiar pronunciations, but I find it additionally annoyingly distracting when the speaker mispronounces words which are not always difficult to say correctly.
It is Rune, [ruːn] not Ru in. which is a derelict building.
The next video started playing , Melee,, is English adopted French and its Mel a ( as in abc, which you might not know how to say as well, an English dictionary demonstrates how a word should be pronounced i.e.[ˈmɛleɪ], but this doesnt help if you cant follow the symbols.
You are not the only one who has done this.
WWM I think also gets melee wrong ,and insists on saying Calv ery, when its Cav al ry [ˈkav(ə)lri].
There is another videoer who also mis pronounces several words, but I cannot remember what they are.
There was insufficient explanation as to the cost of using sets
Finally, you failed to mention that the whole point of having sets, is not to save you time in swopping equipment, which can be done for free, without the need for sets, but to reallocate the heros skills within them.