“It is important to stay with the same size and Load Range (Load Range is not given in this question). We always recommend staying with a brand you are familiar with, but there is no reason one cannot change brands, just not the size. If the performance of the Michelin has been satisfactory then I would see no reason to change.”
And I fully concur with Walter. All things being equal (size, load range, weight rating, wheel spacing, etc.), it is permissible to change brands. Many RVers do so to save money on tires that may be “on sale.” But be sure to check the age code on the sidewall prior to the purchase. It is important that new tires be truly “new.” It has been reported that many tires available at the retail level, though not used, may have been warehoused or stored for a lengthy period of time prior to being sold. Remember, it’s the actual date of manufacture that is important to you, even though the warranty time begins typically at the time of installation.