Levelling general up on subs -strange things happening

Hi. I'm a total noob, but I'm lucky enough to be well directed by my alliance.
Something really weird keeps happening to me this afternoon, though. I've been trying to level up my generals at a blue sub, but while it went perfectly for a while, even with level 1 really weak generals, I've started getting killed with no particular difference.
It's particularly weird that I still get no killed with green weak generals, while siege generals get me killed.

I'm using 45K T10, 22K T9 to T1. When I started, with zero kills for at least the first 100 hits with different generals, I was using 30K T10 and 21K T9 to T3. Ironically I started getting some killed the moment I put my best general (yes, it's a mounted general, but still) + a weak assistant, rather than just the weak generals on their own. And now, assistant or no assistant, it's a lottery whether I get some siege killed or not. But my weakest general (a green general that I'm going to throw out as soon as the power growth stage is over) keeps getting no one killed, while stronger generals with siege buffs do. I'm not changing anything else, I'm using a siege preset and siege monarch gear.

I'm attaching two reports as an example, but sometimes the wounded have been up to 1.5K.

https://preview.redd.it/fryyg8lp8dbd1.png?width=1205&format=png&auto=webp&s=1f8051645cf2833e701b5b8950a1690befb5a1e3

https://preview.redd.it/3efdkehq8dbd1.png?width=1205&format=png&auto=webp&s=93d497d35a5f6312892870a55000a6dff87c7a90

I really don't understand what's going on. I've tried going without T1-T2, I get more wounded. I added 15K more troops to my T10. I added 1K more to my T3-T9 layers. I added 20K T1 to T2 (because at first I was going without with no issue). Still nothing, some killed with some generals with no real pattern I was able to discern -- adding those two layers did reduce some of the killed, though.

I tried going with both generals, one as an assistant. 100 wounded. I change generals, 1K wounded! what's going onnnn? Eliza's literally my worst general, why is she the only one getting this right, lol!
(Particularly irksome because the 100-200 first hits were all correct, and now I'm going crazy)

Any theories welcome, and sorry if this is a noob question.