Both of my suggestions have warfare mixed with fantasy, but you could try them to see if they scratch your itch.
Drifters: famous warriors get isekai'd to a fantasy war and start waging a war on behalf of the subjugated elf population.
Gate: a portal opens up in Tokyo and fantasy creatures try to invade Japan, only to find themselves against a modern day army.
Bonus suggestion: Full Metal Panic. Mecha battles against terrorist organisations. The first season is a mix of serious and funny, following ones are more serious in tone. FMP Fumoffu is a spinoff with just the funny stuff. One of my all time favorites.