I need help with dog food! Please help!?

Hi.. My husband & I have a 9 year old chihuahua named Maya. We feed her Blue Buffalo Healthy Weight Chicken & Brown Rice. Last week we adopted a pug named Kelly that is about 4-6 years old. The shelter was feeding her Wellness Lamb & Sweet Potato. We decided to keep her with the same food so it won't mess with her stomach. The person at the shelter to us they like Kelly's food because it helps her with her coat... I want to know if we can stop giving one of the dogs the food they are currently eating and just stick to one brand. If so, which one is good for both dogs? Please help!! Hi.. My husband & I have a 9 year old chihuahua named Maya. We feed her Blue Buffalo Healthy Weight Chicken & Brown Rice. Last week we adopted a pug named Kelly that is about 4-6 years old. The shelter was feeding her Wellness Lamb & Sweet Potato. We decided to keep her with the same food so it won't mess with her stomach. The person at the shelter to us they like Kelly's food because it helps her with her coat... I want to know if we can stop giving one of the dogs the food they are currently eating and just stick to one brand. If so, which one is good for both dogs? Please help!!