Heeded your wedge comment

Question
I was doing a practice session at Adm Baker this AM with my wedges.  I decided to take the 64 deg out of my bag (it is a bit finicky anyway).  I had much better success with the 60 doing the "downhill lie,ball below feet, downhill to a pin 5 feet from the edge of the green" shot (I hit a little bit of a cut shot). Not only that, the 60 is great from those "concrete" bunkers found on quite a few San Diego golf courses. My sand wedge still remains my goto club for shots over 15 yards.

There is actually more value added carrying both the Ping G2 and Titleist 975D drivers (besides, I still have only 12 clubs in the bag with both).  The former is a little easier to hit but I tend to have a small fade.  The latter is easier to shape shots and I hit it very straight when I pay attention to my swing.  Both clubs have great feel (and have the same swingweight D1; the G2 is 44" and the 975D is 43.5").  The only thing that may preclude carrying the Titleist would be if it lost in a contest with my 5 wood (I hit the latter between 200-210 STRAIGHT and just about never miss with it); I played my best two rounds of golf at National City teeing off with a 5 wood (3 over par from the white tees and 4 over par from the blue; I almost "greened" a so-called par 4 from the white with it).

Answer
No reason not to carry both drivers if you have the room.  J.C. Goosey, a former tour player and owner/operator of the SpaceCoast Golf Tour carried two putters; a short one for long putts and a long one for short putts.  He was shooting his age well into his 70's until the big C got him.