The rules are my own adaption of classic Piquet for fighting larger battles than that for which the original rules were devised - at least that's how they started. Although I call them version 2, they are probably version 10. The original adaption pre-dates the publication of Field of Battle.
They still retain the sequence card element (revised), and the up and down opposed dice combat tables (revised) but, the way initiative is won and used are different; the command group and movement rules are different; the post combat rules including rout & pursuit are different; etc. Some of the new rules come out of ideas in Field of Battle. A lot of stuff I've developed myself during hundreds of hours of playtesting.
In short, although recognisably classic Piquet (as written by Bob Jones) with some elements from FoB (by Brent Oman) it is a very different set of rules to those commercially available: rewritten cover to cover in 30 pp, not including the army info stuff and tailored to be specifically WAS & SYW period, and central European theatre specific (I have Prussians, Austrians and Russians so I didn't bother writing them for anything else).
I'm happy to play classic Piquet providing the unit count doesn't exceed about 16 a side, and I'm happy to play FoB for large battles if that's what people are used to - the latter have a growing following because they do produce exciting games. However, I wanted something of classic Piquet's asymmetrical initiative (I don't use opposed D20s, I use domino theory, using dominos), characterisation decks and morale challenge rules streamlined for battles involving a lot of units. I've used an earlier version to refight Zorndorf (about 90 units all told) with success - classic Piquet would simply collapse under the weight of numbers.
Hope that's enough info, feels like it

.