mental?

I would disagree about her knowledge of war. The only two engagements she’s been in prior to this were against the Antinium and the Goblin King. In both cases, she would have been leading people against armies that vastly outnumbered her own. Those would produce a very different picture of “are we winning”.

She also wasn’t exactly acting as a commander or strategist of any kind in either situation. In the Antinium war, she simply rallied the humans and brought them south, but there were other people acting as the actual commanders of the human forces. Against the Goblin King, she participated in the Sacrifice of Roses – which was mostly a defensive holding of the line while getting slaughtered – or led a group of plant golems against the goblins – which likely isn’t anything close to leading people.

This is the first fight she’s been close to that was relatively even on numbers. It’s going to be much more difficult to tell if her side is winning or losing in a fight that is as “small” as this one is, compared to the others. She also hasn’t really had the time to fully plan everything out like she probably wants, both because she has received far less support than she anticipated, and because Zel has only been around for a few days and has had to deal with a hugely mismatched set of levies for his army.

In other words, she’s basically only a “war hero” in name, rather than being an actual fighter herself. She knows how to pull people together for her needs, but not how to actually lead them in large-scale combat. Her scheming and cleverness have been mostly nullified due to insufficient time and lack of resources.

The exploding goblins seem to be Az’Karesh’s creations, rather than those of the Goblin Lord. Az’Karesh would have zero qualms for making goblins produce babies, then killing them deliberately to make undead.

It’s also possible that the Goblin Lord does create them himself, in which case they are probably made from naturally occurring deaths of goblin children – I imagine even in a tribe the size of his army, there are still natural deaths due to accidents, diseases, poor health, etc. The parents might give permission in that sort of case.

I believe the terrain was described as a mostly-flat plains/grasslands area, though due to the weather it’s quite churned up and muddy at the moment. There are likely a few low hills, like the one Magnolia and co. seem to be on, but only enough to give them a bit of height to oversee things, not provide any major tactical considerations.

There is at least one spell that likely does something similar to this, that we’ve heard of: Valmira’s Comets.

That being said, I’m pretty sure that spell, and anything similar, would all be very high level magic. You’re probably going to need to be a level 40-50+ mage to cast those, normally.

I would also imagine creating magic far enough away from your body would require an exponential cost of both mana and skill. Spells like Valmira’s Comets, and Grand Fireball and such, likely are composed partially/mostly of mana itself, rather than physical matter. Creating enough real matter, at a high enough point to really produce an effective kinetic bombardment, would probably require astronomical amounts of mana, as well as time to actually cast.

Metal magic should be mental magic, I believe