Ninja and Assassin

Hello everyone,
What is the difference between Ninja and Assassin? Assassin has an instakill and Ninja does not. To make up for that, Ninja has more mobility and other utility items such as Invisibility and Flash Bombs.

But it seems the game is moving towards and instakill-free playstyle, which I agree should happen. What worries me however, is what will be the difference between Ninja and Assassin once Assassin has it's instakill removed? They already have the same role, recovery, so with the defining ability between the two classes removed, they'll be very similar.

Historically (according to wikipedia, which is enough for this, right?) Ninjas had three main roles: Espionage, sabotage, and assassination.

If we wanted both classes to be unique and make sense according to their names, Ninja would have to take up either the role of espionage or sabotage, assuming Assassin's role is assassination.

But what place in this game does espionage or sabotage have? Let's look. The definition of espionage is:

"the practice of spying or using spies to obtain information about the plans and activities especially of a foreign government or a competing company"

The definition of sabotage is this:

"destruction of an employer's property (as tools or materials) or the hindering of manufacturing by discontented workers"

What information is there to gather in CTF about the other team? Where the flag carrier is? We have a compass that does that for us. Enemy health values, perhaps? We have Medic. Otherwise, a class based around this role would be very boring, from what I can see.

What is there to sabotage in CTF? Engineer and Necro structures? Maybe, if either of those classes were worth playing. Anyway, a class designed strictly to counter another is never a good idea. Look at Elf, for example.

If we combined both the roles above into one class, it would still not be suitable compared to the rest of the classes. They simply would have more value in a game than Ninja with those two roles.

My solution to the problem is to rework and rename Ninja. There has been a lot of talk of a Scout class, that would have a similar playstyle to Ninja, but a different role, to guarantee unique gameplay.
This solution may seem radical, especially to those who don't believe there is a problem at all, but in a game that desperately needs renewal, I think this is a good idea.

Tell me what you think!
Thank you.