Inside tread werar on toad

I thought my tahoe was out of alignment saw tire wear on the inside front tires, only have 10000 miles on them. I have towed the car 5000 of those miles, to my amazement the font end shop said the cars alignment was perfect? well why the tire wear? they told me the bridgestone tires had softer rubber and tread design was also a factor when towing, suggested a closer tread design. I have used Michelin tires on vehicles in the past with no problems. any body had this problem with the tires? what did you do to solve it?