I made it to level 20 and thought I would leave an update for any interested in such a strange level split (8 fighter\ 6 monk\ 6 pally). I am enjoying it enough to run through an Epic TR I think.
I am finding some of the synergies in the build interesting. Jyhdif has a PRR of 59 at the moment in earth stance with iron skin and sacred defender PRR bonuses (and a defense +4 item). If I swap in combat expertise, he can gain another 20 from the Legendary Dreadnought tree, while he is running with it, although he will probably use Power Attack for the momentum swing/lay waste options, assuming the cooldown clearing effect of cleaves works on them now. If I can get a sheltering item, I think his PRR will be in the decent range.
Although ~60PRR is not great, I find it is sufficient so far to avoid sudden death against heroic elite champions. The added healing from the Paladin levels is great and I swapped him to a FvS dilettante for the healing scroll usage, at least until he gets some healing twists of fate or replenishing Lay on Hands.
Although I thought the monk levels would not add much beyond the 30-45 PRR, earth stance adds a +1 crit multiplier to all 19-20 attack rolls, and fists of iron is quite impressive as a 5 ki, 3 second cooldown strike (+3[W] damage, +1 critical threat range, and +1 Critical Damage Multiplier). This leads well to the Earth Earth Earth finisher, which adds 2 to the critical multiplier. Although I will probably switch him to a TF Falchion when I have the ingredients, If I kept him with the Riftmaker (just the level 14 version), with a capped Legendary Dreadnought tree the weapon would be something like ~3W(1d12)/ 18 x 5/ 19-20 x 8 passively! As a fighter monk pally, I am constantly cycling through his attacks, and the LD tree only expands these, so with Momentum Swing, Lay Waste, Exalted Smite, Fists of Iron, the crit multipliers are even higher (and the range slightly higher). I know this crit range is horrible compared to most other builds, but it will be fun seeing the rare x9 or 10 crit while blitz is running! With haste boost, 20% damage boost, and divine might, his burst damage is pretty decent.
That said, most of this could be done better with a pure Paladin, except evasion. Perhaps that is the next life for this one.
For any interested in strange build options, I actually think this build could be very interesting with unarmed, whirlwind strike, and more investment in the KotC tree. I am sure there is someone more skilled at character building than me that could come up with something amazing in all this (e.g. I believe Kensai Keen does in fact work with unarmed and stacks with imrpoved crit, so you could actually get a crit range of 18-20 with handwraps and 19-20x5 in earth stance with overwhelming and devastating crit, so some better looking crit profiles, and exalted smites and fists of iron could add to this). The "Deadly Strike" tier 5 active attack in Kensai, while limited to the number of attack boosts you have (only action boost attack, for some reason), is a guaranteed critical and adds 500 damage on vorpal. The other Kensai tier 5, a good death, adds 500 (scaled by something, I think, as Jyhdif hits with it for ~750) when the mob is below 20% health. As the build is already based on constant attack clicking, adding in those two in the beginning and end, respectively, works well.