It's not practical if you think about it.
To support a big military to conquer on higher levels you need gold, so you need to maintain trade routes, sell luxes and build gold buildings/hold off on other buildings.
-you're likely to be embargoed if you keep attacking everybody You won't attack everybody, you'll only attack your science competitors. Also, you're likely to be embargoed also when pursuing an agressive CV (and of course when going for domination), but yet is seems to be the most effective way to achieve it...
-you're not likely to have good relations with a warmonger penalty, giving you less gold from trading luxes. True, but, I'm qouting myself: "you're likely to be embargoed also when pursuing an agressive CV (and of course when going for domination), but yet is seems to be the most effective way to achieve it..."
-you're going to need to use hammers on gold buildings. True, but it's really annoying to copy+paste the same thing again and again.
To actually win a science victory, you need science= population+ science buildings.
-you need to use a lot of hammers on science buildings, which by the way, burn gold. You'll spend hammers on science buildings anyway.
-You'll need to constantly be growing which means you need a constant positive happiness. Which isn't easy while warmongering. True.
-if you neglect culture you're going to be in a huge happiness ditch pretty fast. Neglect culture? You are likely to get some GW with the cities you will conquer...
All in all, war all day every day is almost certainly a bad idea, even with assyria. If you're going for tech with Ashurbanipal, it'd probably be a better idea is to scout early, use seige towers to take out your highest-teching neighbor, then sit and grow. I didn't say you shouldnt' do that.