SEVEN different brands of tires on my truck

There are SEVEN different brands of tires on my Century Expediter

Steer: 295/75R22.5
L/F is a Dunlop SP384, which is in good shape - no dry rot and good tread.
R/F is a General (Continental) S580, also in good shape.

Drive: 295/75R22.5
L/RO is a Hercules S307, also in decent shape
L/RI is a Yokohama TY577, also in decent shape
R/RO is a Goodyear G662 RSA, nearly new
R/RI is a Bridgestone M726EL, acceptable shape (and passed DOT inspection last week)

Drop axle: 255/70R22.5 (noticeably smaller than the others)
All 4 are BF Goodrich ST230, also in decent shape

Anyway, in discussing tires with the old commercial tire salesman at AOK Tires yesterday, he said in his experience cheap Chinese tires were safe and blowing out wasn't a concern, but he cautioned they didn't seem to last as long (obviously they sell all kinds of tires so I'm reasonably sure he was telling me the straight story). Moreover, since safety is such a paramount issue in America I rather doubt Uncle Sam allows unsafe tires to be sold and thus, I am actually (surprisingly for me) OK with using el cheapo tires.

Here's what I'm thinking of doing. I'll buy one additional Goodyear G662 RSA and putting these on steer. Then I'll opt for four el cheapo Chinese for the drive tires. As for the drop axle, I think I'll leave well enough alone because I hardly ever load the truck sufficiently to need them.

Finally, I'm not in any particular hurry to do this because the tires really are OK still (else I would buy immediately). It just bothers me to see the variety, but since there's no safety issue involved, it doesn't bother me enough to move with alacrity to spend another 2500 bucks on the truck right now especially because I just forked over the dough for tag and taxes when I registered the truck yesterday.

Regardless, is there any cause for concern with my thinking?