I was looking at some things and I ended up scratching my head a bit.

From my understanding with a standard cleave ability from a weapon etc... that you can put that damage on another figure that you could have also attacked so those figures do not need to be adjacent.

When I first read Gaarkhans Brutal Cleave I did not read it carefully enough thought it worked the same way.. Then I reread the card and found out that the second attack has to be on a figure that is adjacent to the figure you attacked.

Thoughts as to why FFG would do this? seems kind of confusing? would that have made the brutal cleave ability too powerful? Does that still make this the better of the 2 top cards for this character? or is unstoppable the better of the 2 then? now I am not sure which 4 XP ability to take.

Brutal Cleave is not Cleave. It gives a new attack, and because of that Gaarkhan can declare to use a different weapon, and it is perfectly valid to use a ranged weapon for that attack. Are you still thinking limiting to a figure or object adjacent to the target (figure or object) is not needed?

(Also, Cleave is not "could have attacked", but any target you can attack after the attack has resolved. I.e. if you defeat a figure or destroy an object and have Reach, you may be able to Cleave someone behind the target of the attack, because the target no longer blocks line of sight.)