Doesn't matter how much you sweat, it matters what you do with them after the workout. If you wash them or even just let them air out after use, it's not a problem. I have 15+ year old synthetic shirts which have been on dozens of 5+ hour mountain bike rides in 80-90 degree weather and they don't have any scent at all.
That's exactly what I do. Hang them up after riding (on a hanger in the garage) so they dry, then wash with normal detergent and sometimes maybe a bit of powdered OxyClean (sodium percarbonate).
I've had phenomenally gross post-ride jerseys (literally crusted with sweat), but doing this they don't get stinky. I agree that the key is to not let them stay wet and let bacteria grow in it. Get them dry fast, all is good.
