I had decided on my leveling path when I saw a forum post (on the WoW General Forum) about a paladin who had been power-leveled by a friend. As I had not really done any long range planning, it hadn't occurred to me to do anything aside from take their leveling path at face value. So I dutifully slogged my way through Razorfen Kraul from levels 20-24 and intended to get to 25 there before moving on to the Scarlet Monastery. Then I happened to do a quick check and realized that you can zone into SM at level 20! This changes things...
Mind you, RFK is not a bad instance to grind out with my small group, but the Scarlet Monastery provides a change of pace and a nice dash of variety. It has four separate wings, and each one is short and linear. And since the group can zone into all of the wings, the experience is excellent. The graveyard is the poorest in this regard since many of the mobs are non-elite. But it's also a very short and very quick clear. The relatively poor exp, small selection of useful loot drops and fast respawn on trash makes it likely that I will not spend much time in there. But there are three other wings.
A full clear of the four wings and a second run through the library got the team to level 25 and about 30% shy of level 26. I will run SM a few more times and then give Razorfen Downs a shot just to mix things up, and perhaps even run Blackfathom Deeps once or twice. BFD is in contested territory and the instance portal is inside a winding and confusing series of tunnels, so I am not sure it's worth the potential headaches just for a quick run or two. RFD may give me the opportunity to experiment with involving the whole group in the fights. But I get the feeling that I won't really have anything to worry about until the group is in the low 50s.
I will try to remember to get some screenshots of the team. I would also FRAPS a movie or two but I think I'll wait until I can get the entire team involved before doing that. Otherwise it's just a video of a level 70 enhance shaman plowing through instanced zones that are 30-40 levels lower than he is.