You could ask someone to give you some ghost starters so you can manage up to Corey. After that Drifloon becomes available. (which works pretty good against Shelly of I might add.
Replace Cacnea with Growlithe,because he will learn Flame Burst at level 28 and you can change the field into a Burning Field!And level up a little more..
Tomy, it is either you use Zard-Y instead since it has a Modest Nature, which would hinder a Zard X or you will have to breed yourself a new Charizard with Adamant Nature.