Yes, looking at the long term trim numbers can help point you in the right direction while troubleshooting other problems.
Injector problems are very rare. Lazy or small leakers are almost impossible to detect as the ECM will correct for them (fuel trim)
If you have a failed injector (doesn't open, or stuck open) then this may show up as a misfire.
One of the great things about modern fuel injection and ignition, it makes troubleshooting problems a lot easier, if you know how to interpret what your looking at.
I was fighting a P0171 LEAN code on my Toad, a Saturn Vue. The car ran great except it would throw an occasional 171 code.
The main problem was a very, very small air leak from intake manifold o-rings.
A contributing factor was a brand new MAP sensor that wast providing correct pressure readings. It showed 15.2 psi with engine stopped. I threw in a used OEM sensor, that showed 14.7 psi. The 14.7 is correct for my altitude (sea level) This is minor difference that the ECM would have corrected for had it not also had a small manifold leak.