I would liken it to Icewind Dale meets XCOM in a FO Tactics like setting. All focus is on the party unlike mainline FO which is all about the player character, with the option for companions for combat only. In Wasteland 2 you need to have a balanced group in order to utilize all the skills in the game because no one person can do everything, really no one can do more than 1 or 2 things well. So in order to gain access, open up dialogue options and complete a lot of quests you need a well balanced team that covers all the skills.
At least with the original release, they may have re-balanced them for the DC, custom party members were better than almost every in-game companion due to poor skills and attributes they come with. Of which there is little character development for most of them as well, so you don't lose out on a whole lot by not using them. There is a story but it's not super deep, though it is well done and engaging, nor is there a very strong narrative as you really aren't anyone. You are the Ranger Party. No one individual in the group really matters, especially with the way the speech skills and conversations work.
Combat is a lot like XCOM, more than anything else, in the general sense of using varied cover, stances and all of that to position yourself, use AP to move or attack and so on. Though combat is far more forgiving, but you can easily lose a party member if you aren't careful or get an unlucky roll. It's also grid based which can be a real pain in the ass, because out of combat play is not, and you can position your party in what looks like cover and specifics spots and then once you initiate combat they'll all snap to the nearest approximate grid space which might not be where you wanted them. Leaving them exposed and out of cover or bunched up and in a group.
