Baby formulas follow strict guidelines. This doesn’t leave much room for companies to make their brand wildly different from another brand. So, there is not a lot of difference between formulas from different brands as long as they are of the same type. This means you can seamlessly switch between them without causing any problem for the baby. Moreover, you can even try mixing two different formulas of the same type. The only problem is that the baby might take some time to get accustomed to the change in taste.