Because Asians are so precocious there is not so much gained by pruning by ratios as long as branches are smaller than trunk and don't starve the leader if you intend to keep the tree central leader.

Pear branches are also less prone to breakage because of sharp angles as other species but you still probably would want the branches spread. If branches are too thick it becomes more difficult to spread them without bending the leader instead of the branch. A hinge can help for this.

Thanks again.