Is it more fun than looking for hours and hours for animals you can fight that offer no real rewards for the fight?
Yes you can get crafting mats, but after you kill 5 or 10 of them you don't need that many more mats, other than to grind a skill (which a combat player might not even want to do).
So you need like 100000 attacks on animals to max out a skill, how many animals and weeks would it take to do? Is killing animals hard? HECK NO. But you kill an animal in like 3 to 10 hits on the type of animals you would be training on. So you spend 30s to 1min killing an animal you get lets say 10 skill ups on. It will take 10000 animals to get to max level, which is already lets say 30s x 10000 = 300,000s or 5000mins or 83.3 hours.
BUT!!!! You also have the 1min to 1 hour time between fights LOOKING FOR AN ANIMAL. So now it goes from 83 hours to like 2000++++++ hours!
So the real problem is not scaled skilling on animals.
Killing a rabbit, should give a max skill gain per attack of very very low, killing a platebackbear should give a max skill gain of very very high.
It would encourge people to fight animals/mobs more in their skill range.
This is why people use Rev's to train up on a lot because they are common in a tribe area and they take a few more hits to kill.
Skill gain should be based on damage done, mob level vs skill level.