They may not be the best people, but when we are over and done you will have the same expression as the lionesses above.

Ok, imagine this. normal day, just minding your own bushiness when all of the sudden a dead Prince appears. Sounds pretty extreme, right? but that is exactly what happened!

Scar told everyone that Simba died, so as far as everyone knows the Prince and the king are dead. No one has seen Simba sense he was a cub either. You wouldn't know what that cub would look like as an adult! but all of the sudden  the cub that died in a stampede suddenly comes back wanting to claim rights to the thrown. Just a small bit suspicious.

Even if you believe all of that, the "prince" then admits to killing the old king. So not only is he dead, but a murderer as well!.

The present king (Scar) attacks, after fighting a while the supposed "Simba" has Scar held down, paw over his neck, in a position where "Simba" can easily kill him. The dead "Prince" makes the king admit to killing the old king. 

This entire thing makes absolutely no sense!!!!!!

I would be SOOO easy for a power hungry rouge to claim Simba's identity!!!!!

I do understand that the lionesses attacked Simba as told in the "Lion Guard", but can you blame them?