You could just print out that linked guide and use Questhelper to guide you. I have not used this guide.

The zone progression in the first part of that Horde guide is:
Durotar 1-5
Eversong Woods 5-12
Ghostlands 12-21
Ashenvale 21-26
Barrens 26-28
Stonetalon 28-29
Ashenvale 29-30
Thousand Needles 30-34
STV 34-36
Arathi Highlands 36-38
Dustwallow Marsh 38
Arathi Highlands 38-40

Personally, I didn't like any of the add-on quest guides that I have tried (not the guide, but the add-on part). I typically use a printed out version of whatever guide I use (most often wow-pro.com guides). I haven't come across many that are geared for multiboxing, nor any that have been updated for RAF or other "XP" changes. So, I just stick with typical guides and skip collection quests. However, this is definitely still not efficient since you spend a lot time in a single zone and eventually out level the guides and never venture into many zones. I'd imagine if you were to maximize XP gain, you would only do a few select quests in each zone and move on. I have yet to see anything beyond the linked guide that attempts to do this. However, I am sure with some research and work you could go through a decent guide and formulate a plan.

The one thing I recall is that I thought The HInterlands was a great zone to multibox in. Most other pre-Outland zones are pretty meh...

It typically took me a little over 2 days played to level my teams to 60 with RAF (with no level gifting and only PVE questing). So, definitely not the best since many claimed to do it in 1d. I managed 18 (I think?) level 60's at the end of my RAF (I had 2 accounts prior to RAF and added 3 more, so I missed out on a fourth RAF link as well). To accomplish this I leveled two teams to 60 and two teams to 31. I play very casually, about 2-3 hours a night. So, although you may feel it is taking too long to level, I'd imagine you will easily meet your goals within the RAF time period.

This probably didn't help much, but my main point was that leveling without maximum efficiency isn't really all that bad. Also, I always felt that 1-40 was really slow, likely due to how the quests are spread out all over some large zones.