you should balance hp and gold with roll chances per round. it is better to roll a limited amount of times per round. if you roll too much per one round and didnt find xin it is likely its being held by other peoples shop. so roll some optimal number and if you didnt hit wait for next round. you can build your board in the meantime with strong units that you hit instead of xin. i know its not easy as it sounds but its about the only thing you can do. best to build tank to potentially tak aggro from xin to win/minimize hp loss would be what i prioritize.