Thanks, David Gaider said something similar that he recognized the lack of screentime by the the non-companions when saying he prefer companion romance; however, recognizing it and overcoming it are two different things. For one thing, it's more personal having companions fighting next to you as well as having them participate in the cutscenes. I have never seen the "lead" romance in any game with followers participate as NPCs. NPC romances can only participate in cutscenes. While Steve and Samantha have the same amount of cutscenes in Mass Effect, it doesn't feel very equal. I remember the developers saying somewhere that romance budget is around the same amount, but it was a long time ago though, so I don't know if they change, but if that's the case, they couldn't have devoted a lot more extra scenes to balance the NPC romances. I feel like Cullen and other NPC romances (Likely scribe girl) may get the short end of the stick.
It seems to me that Bioware may have found a solution to the NPC romance options not being involved in combat this time around by involving them in other aspects of gameplay. This of course is going to depend on how the keep and agent management system works, but it seems as though Cullen and Scribe Girl, the two most likely NPC LI's could be heavily involved in this portion of the gameplay. It may not be combat, but it is something more than just cutscenes, and could, depending on how it's handled, be a way for the player to develop attachments to these characters outside of the traditional Bioware dialogues.
This is of course pure speculation, but I'm very eager to see how it turns out.