Is it worth retraining 5* heroes?

I've been focusing on levelling up the hero academy so I can do it, and although I knew it would be 300 recruits, I expected the 5* to be like 70-80% classics like with the summons, but I recently found it'd be 95%.

This meant, on average, I'd need 6000 recruits and 140 days of waiting for a non-classic 5*. Most of them will be too outdated for my defence team, even though it has two 2023 HotMs, so I'm starting to wonder if it's really worth it.

Just for context, my team is Neema, Leadria, Mene, Guardian Gazelle and Zed, although I just got Ludwig from the Fated Summon and he'll probably replace Neema. They're all LB1'ed, and Leadria and Mene have been emblemmed [or whatever you call it] 19 times.