Well, the video on the website shows a bit of combat. They summon an ice elemental which is quickly destroyed, leaving some ice on the ground. Then they cast a fireball on the ice in order to melt it and finally hurl a lightning bolt at the water which kills both opponents standing in it.
For me, it seems natural to choose turn-based combat if you want a system that can do this. It would be possible with real-time combat and an active pause as well, but if you'd be pausing the game a lot anyway, I think it's better to go for turn-based combat to start with.
Yes, it disrupts the flow of the game, but so does reading the available dialogue options and choosing one. Or opening a window with available loot and picking the items you want to take. It doesn't bother me. And I think combat looks very promising in the video - much better than anything I've seen in a long time.
