It's also a bit tragicomical how it hoses my berserkers harder than my spellcasters.
And it is changing combat - first strike is a free hit. It's just that it randomly changes combat, and if you're using wheytwut for the last hit you need to pay 8 mana and account for any accidental exploration you may cause, and have a fail chance, while at the same time getindare does it's job for 3 mana, no exploration and no fail chance. And if you're using wonnafyt you need to cast a bunch of them before you can cast the relevant one, and it has a random miss chance.
Also, getting stuck with magic resist monsters blocking your corridors can be really annoying and makes wheytwut strictly inferior to endiswall of all things, especially in cramped maps where you don't want you 8 mana investment randomly failing. Sure, you can wheytwut somethign else, but, again, if you found endiswall instead of wheytwut, you'd be free to explore anywhere... And investing in a wheytwut on something else to run into a magic resistant guy several steps into the corridor is a bit deathtrapy, and has on occasions happened
Anyway, maybe there are important reasons behind it all, who knows, but the random IMAWAL fails (or multiple ones) are very silly. You can avoid them, sure, but then, why have to?