Added 10 minutes later
For a faster game, it obviously doesn't make sense to invest in the city – they'll come and destroy it, and the city's growth isn't worth the investment. I play as the Elves in such games; some units of level 6 and 7 don't need to be upgraded immediately, like level 3. In this case, +1 Banshee per week won't make a difference. But I've already tested this with several races, and the Necropolis faction has become noticeably stronger. However, I was playing against the AI, and I think playing against other players will be more challenging than before.
Added 4 minutes later
Nargott, how do you see these two units? – I'm talking about their HP and other parameters, but with the abilities they already have, it all looks pretty good. And another question – did any creature have this adjacency bonus before? – I haven't seen it.