This game won't have limited stamina or equipment fragility - which means it automatically has better mechanics.
As for combat, I found BotW's fighting to be slow, awkward, and clunky. I've also played both Hyrule Warriors Legends (3DS port) and Fire Emblem Warriors (Switch), and they both have more interesting and fluid combat than BotW - so logically Hyrule Warriors 2 will also have better combat than BotW.
Lastly, I never said the first Hyrule Warriors was "hot garbage"...did you get that from someone else? Sure, I do prefer Fire Emblem W over Hyrule W due to streamlined mechanics and stuff - notifications no longer overwhelm the player, Anna appears in the middle of an indicated fort instead of a Gold Skulltula just being somewhere within the vicinity of the indicator, better menus and "History Mode", etc. - but Hyrule Warriors isn't "hot garbage".
One thing Hyrule W has over FE W is the roster of characters being significantly more balanced; FE W has 11 guys, 19 girls, and 2 both (Corrin and Robin), who by default are female and male respectively, so really 12 guys and 20 girls. There's also only one male axe-wielder, and zero male spear-wielders. Meanwhile, H W has a roughly equal number of guys and girls, and what weapon characters use isn't nearly as important.