Disclaimer the first: I worked for Dreamscarred Press for a time. I was there to work on psionic material, and at the time, Path of War had already been published, so I didn’t particularly have much input on the original publication, but I worked with a lot of the people who worked on it, and one of the goals then was to heavily errata Path of War. So that may represent something of a conflict of interest here; we’re talking about work by people I consider friends.
Disclaimer the second: I have lots of experience with new players playing initiator characters—but almost all of that is with Tome of Battle, the 3.5e book that inspired Path of War. My experience with Path of War is almost exclusively playing with the people who wrote it, so that’s about as diametrically opposed to “new players” as you can get.
Anyway, though, based on my experience and expertise, I’m fairly confident that your proposal here should work fine.
Basically, relative to mundane martial classes, initiators are somewhat more complex to build and play when you set the bar to “is a complete and rules-legal character/turn.” Initiators are vastly simpler, however, if your standard of success is more like “is a viable and compelling presence in the game that contributes on a reasonably equal footing with magical classes on a wide variety of level-appropriate challenges.” Building and playing a mundane Pathfinder warrior to that standard is very difficult, but not at all difficult for an initiator.
Finally, even at the standard of “is a complete and rules-legal character/turn,” while the initiator is more complex, it’s not much more complex. In my experience, new players have absolutely no difficulty understanding maneuvers, even if it is an extra thing they have to learn. And picking out maneuvers is far easier than picking out feats, or even picking out spells.
I do want to highlight some differences between Tome of Battle and Path of War that warrant some consideration, though. Path of War initiators don’t just have maneuvers—they also have some secondary thing going on that is generally far more complex that the extremely minor add-on features found on Tome of Battle initiators. Where a warblade gets to add their Intelligence bonus to a few things, the warlord has the entire gambit system, etc. These often tie into the more complex maneuver-recovery systems that Path of War uses—instead of just “spend \$X\$ action, recover all your maneuvers,” Path of War initiators have to do particular things, and only recover a portion of their maneuvers, and on top of that get extra benefits besides which may mean that “recovery” is a strong option even when there’s nothing to recover. It adds an extra dimension to choosing how to spend your turn, relative to Tome of Battle. That may be daunting for a new player.
Further, note that, compared to Tome of Battle, Path of War is higher-power, and also that Pathfinder mundane martial classes are lower-power than their 3.5e equivalents. This means that, while Tome of Battle was a paragon of balance in 3.5e, Path of War is notably strong in Pathfinder. Pathfinder spellcasters are still extremely strong, of course—in practical terms, I’d actually say stronger than 3.5e, because although Paizo did remove (or not reprint) some of the worst theoretical abuses, they gave spellcasters so many neat little toys that it’s easier for a spellcaster to dominate a game in practice. So as long as your Path of War characters aren’t sharing the spotlight with fighters or monks or whatever, balance should be more-or-less fine. New players having higher-power characters is even kind of a good thing, since it gives more room to make mistakes.