This game is great. So many unique philosophies of rating players. I evaluate pitchers on every category. You can find value in pitchers that have splits in the low 60s and sometimes pitchers with a vsR split in the mid to high 50s can still be effective. If a pitcher has vsL at 70+ and vsR split at 55, he can still be effective if his 1st pitch is 88+, and his gb/fb + velocity is over 110. I have found that pitchers that have high velocity will have a few ticks added to their k rate. Pitchers with high gb/fb will create more ground balls. A pitcher with 55+ in both ground ball and velocity is rosterable even with low splits.
The type of pitcher mentioned above is not going to make the all star team, but he can be a decent add. In my opinion, this type of pitcher is better than the AAAA pitcher that you add to roster because he is league minimum. You know the guy with 70- control, splits in the mid 50s or low 60s, with 50- vel and 50- gb and all pitches 75-. These type of pitchers will only pitch decent (under 5.00 era) if you have lights out (Houston Astros) defense or if you happen to sign them and they have a career year.
Also, I value control as much as the guy above, but there are exceptions. A pitcher with low control, but high splits, pitches, ground ball and velocity can still be effective in your bullpen. I had a guy where his control was 37, but had splits in the low 80s, velocity in the 90s, gb of 80+ and 1st in the high 80s. He had starting pitching durability and control, but I put him as a long closer that came in during the seventh inning and he had 10 wins and 42 saves. I would not seek out this type of pitcher and pay him a market value salary. However, if he were still around after rule five draft and I needed to fill a roster spot, he would be on on targets of guys you can get for below market value.