Why do I keep getting Chris as a free or paid officer?

Getting Chris isn't too bad at all. Chris can help you with a lot of battlefield gathering work, as well as support you in your RTS missions -- as Chris is a copter type Officer. This means he's got firepower and range. If by any chance you'd like something better, you'd probably want to purchase officer fragments directly by going to the IAP section of the game - the icon below your gold coin counter in the command center UI. You'll know you are in the right place if the window is titled "Recharge". Go to the "Help Yourself Tab", and when the drop down button pans out, pick the option "Officer". This way, you can purchase specific fragments that you want -- if you want to spend real money for it.