I used to be all over the map so to speak. I wanted to sample and understand every black, oolong, green, and white tea (pu-erh was not as accessible as it is today, so that was off the radar). I wanted to taste and know about all teas.
Back then, samples were not so freely obtainable, so I almost always had to buy 4 ounces or 100 grams of each tea. Quite suddenly I hit the wall ... I was overwhelmed with so many teas and realized freshness, or lack there of, was going to greatly impair my path to higher tea enlightenment.
I decided I was going to FOCUS on greens, pretty much all greens. Also back then, really good Japanese greens were hard to get, so I focused on Chinese greens the most and dabbled in Japanese, but I already knew Japanese greens would be my ultimate destination.
Finally, great Japanese greens were becoming available, and this has improved with each passing year since!!! Once I tasted the good stuff from Japan, everything else in greens became secondary.
However, I would say I focus on Japanese greens first, and Chinese greens second.
Sooo, "Definitely focused on multiple subgroups in 1 or more general types of tea ..."