How do certain "multi-hit" skills work?

[Urthdigger]

I could explain how there is more to combat than just that. But it's become abundantly clear that you've already made your decision and aren't actually looking for answers. Otherwise you'd actually pay attention rather than being an endless stream of hyperbole.

[gamepob]

I have to apologize. It was not my intention to insult, be dismissive or anything similar. I do appreciate your desire to help me understand and I thank you for it.
To me, personally, the difference between what I see my char doing and what the actual result of my char's actions are, is because of badly implemented combat system. If I see my char hitting something in the back, I expect this to be the actual result in the fight. Not "Oh, while you were hitting him in the back server decided he is actually already turned towards you".
...

[gamepob]

...
Now, why is this my expectation? Because other games that do have skills that require you to be at the certain position regarding your enemy, manage to do exactly that. I hope you can appreciate my expectations since they are based on similar experiences.
Yes, this game's combat system probably does rely on positioning the most of them all, but doesn't that mean they should have made it more robust? Where in the tool-tips, guide or manual does it say that those added benefits of our skills are to be used only in groups? I think that is your own, personal deduction as a result of you adjusting to a badly implemented system.
You say that's not the case and that there is more to combat than that. I will be the first to agree that there are still things in this game, I don't understand or badly comprehend.
So I would like to present a challenge to you madam/sir. Please, help me understand it without using hyperbole yourself.

[Niwashi]

Are you trying to tell me that in this game you are supposed to fight only in group?

It just means that certain skills work best in groups. A gladiator's skills for drawing aggro are useless when he's the only person fighting a mob, so would have aggro regardless. A conjurer's Raise skill is only usable for raising other people, as he cannot raise himself. A lancer or pugilist's positional skills are sometimes useful solo, but significantly more powerful in groups where there's someone else to hold the mob's attention. These classes all work fine solo, but they work differently solo than they do in a group.

and yet they implemented this system without specifying in tool tips or anywhere else that those skills are supposed to only be used in groups as they are almost ineffective in solo fights.

Well, Urthdigger and Estellios have both pointed out occasions where you CAN in fact get the positional bonuses solo. If the mob is busy with a skill induction or if it's been stunned, then you can get behind it just fine. It applies whenever you can maintain the proper position for that skill bonus, so that's what the tooltip tells you.