Lobo's strings being predictable isn't an issue because he has a lot of options from them. The fact that his D1 on block can lead to a three-way mix-up, as well as a good handful of normals/strings, is really good. His mix-ups don't come from using his strings alone, they come from using his other strings like 21. One of his strongest mix-ups is based around the 21 string; You have the option to tick throw from 2/cancel into hook charge (MB to stay safe)/Low Shot, or do the same with 21, making the opponent guess something like "mid-overhead-tick throw" or "mid-low". From B2u1, you have to block "overhead-low", so canceling from that makes it even trickier for the opponent. It could be "overhead-low-low", "overhead-low-overhead" or "overhead-low-tick throw".
Buffing his strings so he has immediate 50/50's that lead to HUGE DAMAGE would be wayyyyy too much.