I detected some sarcasm in his tone of voice when he made that statement (about "really fun" to have Caroline and Lou on the floor at the same time). It sounded like he was implying that in practice, they are competing to make the same plays rather than playing in a way so that one complements the other.
Really, they are very similar players -- similar in size, skillset, and attitude. They both like to be relied on by their teammates to make the big play when it is needed. But because of their similarity, I can imagine that it may be difficult to have them both on the floor at the same time. They may both have the same major weakness: slow-footedness on defense. Apparently Lou also has issues with passing and ball-handling, which she never had to do at Fairfield.
The small forward position has a lot of competition: Caroline, Lou, Aubrey, and maybe Ayanna. Now that Aubrey seems to have a jump shot (a really big deal if she shows it in games), she could be a contender for big minutes at that position. Ayanna is probably more natural as a 4 than a 3, but there is a lot of competition there too (Aaliyah and Ice), but Ayanna is so talented that she has to play somewhere.
As is often the case in these situations, those who get the minutes will be those who play the best defense, and/or those who fit best into the team's offense.
In a way, it's good that Caroline and Ayanna may have minutes limitations in the early part of the season because of convalescence from injuries, so Lou and Aubrey might get more minutes than would otherwise be possible. It would be wonderful if they play so well that Caroline and Ayanna get nervous about their own minutes, and crank up their game because of it.