It was kinda strange for me, in my first playthrough of FE7 I threw prepromotes (mainly Pent, Louise, Harken, Marcus) at everything and didn't even bother to train my main lords, who ended the game at around level 7 unpromoted (eliwood being the exception due to his forced promotion). Then I went on Gamefaqs and a guide told me that all the prepromotes were shit, even though they worked fine for me. But my 9 year old self was swayed and I stopped using prepromotes for like, 5 years. Then I heard about LTC's and wanted to try that out, which made me come back full circle.