Well. You need only a single mascot for your business or brand. It is the same when you are having a mascot logo. If there are several mascots, it may create confusion among the audience.
Instead of upholding your business, the reputation may drop. When people will find several mascots, they may not decide which one to follow. In this way, the mascots or the logos can create a massive misperception. Hence, it is wise to have only one mascot or mascot logo.