Glad you like your knife, synthetics are really practical for a hard working knife, they don't crack, shrink, swell, rot or loosen and shrug off water, sun, cold and heat.
If I was choosing a handle made of natural materials, I would go for dense Sambar stag followed by a hard, dense wood like correctly seasoned cocobolo, African Blackwood or Desert Iron wood or a professionally stabilised wood and make the knife with vulcanised liners to cushion any movement.
I think unstabilised softwoods would suffer all the problems that synthetics aviod and also affects dense woods to a lesser degree.