You can combine frames with nurse bees from different hives in a long hive without them fighting? I have a long hive and this may work well for me.The Cloake Board system is somewhat different as it produces queenlessness within a box above a QX for 24 hrs or so in order to start the cells, then returns that box to queenright-ness in order for them to be drawn-out by the full colony under queenright (supersedure) conditions - AND it concentrates a large number of bees within that box during the queenless period to maximise the number of q/cells started.
I find that pulling the queen from a reasonably strong colony (and placing her in a small holding box with a frame of bees) will indeed produce a dozen or so q/cells of good quality. The downside of doing this - and is presumably why it's not more popular - is that the q/cells produced may be of slightly different ages (and thus emergence is somewhat unpredictable), they are often drawn in less than convenient places such as against woodwork or supporting wires, and they are often drawn in pairs or multiple clusters which cannot be easily separated. In addition, throughout this queen-rearing process egg-laying has ceased - whereas with the Cloake Board system, it can continue uninterrupted.
Take a tip from Doolittle: if you have (say) 10 good q/cells started within a queenless hive, then ensure that you also have 10 brood frames within that box - i.e. as many as brood frames as q/cells (the use of a Long Hive is ideal for this purpose). Steal frames together with their nurse bees from other hives as necessary to achieve this. When the time comes to cut the q/cells out (say, Day 11-12), attach one to each brood frame. Then, on the day prior to emergence, transfer one brood frame together with both it's bees and q/cell to each nuc box. There's no need then to either protect those q/cells, divide-up the nurse bees between nucs, or worry about bees flying back home.
The Joseph Clemens Queenless Starter-Finisher technique (a cut-down version of Laidlaw's method) can provide modest numbers of q/cells all season long, and is well-worth checking out. Likewise the Rose system (not quite so well known).