Having one theory is setting a limit on your potential and the potential of the overall theory and subject you are working on. Having multiple theories gives you a broader idea and perspective of what is going on, and even though one may slightly contradict the other, it is okay because that is what theories are for.
To the point, scientists usually have more than one theory so that they can gain a broader perspective on the matter and maybe even increase the chance of being correct on the matter.
Hope this was helpful.
Cheers,
During exponential growth the rate of growth accelerates according the the number in the exponent of the base, which can of course vary depending on circumstance.
