Tires: Mazda Tribute AWD matching tires?, AWD Tire Sizing

Question
I have an 02 Tribute with the original tires used only in the summer (studs are on 7 mos of the year).  Car has about 46K on it so summer tires have about 25K max (car used around town).  Just got a slash cut in one tire that cannot be reparied.  Tire shop guy says he cannot replace it with a similar tire...only will sell me 4 new ones even though the tread on the other 3 is "not bad" in his words.

Question:  can I replace the tire with a comparable 235/70R16 or does it have to be the same brand (continental). Tire guy did not indicate that the tread etc had to be new, but several other forums indicated that not only should I have the SAME size, and BRAND....but the tread should be same to protect the AWD.  Not sure whom i can trust to get a straight answer.  i don't have a problem buying one new Continental tire if I need to but I would rather not replace all 4.....
Thanks!@!!!  

Answer
Sue,

You should check with Mazda to be sure, but I believe they will say that in order to protect the drivetrain from binding up - and ultimately failing - the tires have to be very close in diameter.

Not only does this mean the same size, brand, and pattern. but also the same state of wear.

You could probably use a single new tire, but the risk is that the drivetrain will fail and that is thousands of dollars worth of repairs.  This doesn't sound like an acceptable risk to me.