No need to mess with what's working for you. I don't understand, are you having dandruff problems that you need that shampoo for? My husband gets dandruff mostly because he doesn't scrub his scalp enough. If he scrubs it regularly, he's fine.
I always had oily hair, too. Really oily hair maybe would be better to say. I switched to daily sls free and cone free washing. My hair looked sooo much better. I tend to get a lot of frizz. Once my scalp calmed down to where I could get away with missing a wash day (sort of), I switched to daily CO. I'm able to skip a wash day now and I use a very heavy conditioner. I really have to scrub that scalp though. I found that I was drying my hair to keep up with my oily scalp.
On the other hand, if you aren't having dry hair, splits or frizz, it's no big deal. I would only change if it was an issue of getting rid of the oily scalp thing. By the way, stretching washes was a disaster for me. I had to do the stages to make it work. Milder shampoo, stretch now and then, CO stretch now and then. That's the only thing that worked for me.