Peculiar identical events from two similar models

Hello,

I’m trying to generate events for two different BSM models: (1) the W+W-H coupling is negative and (2) the ZZH coupling is negative. I will refer to models (1) and (2) as sm_mkw and sm_mkz respectively. For each model, I’ve changed just one line in the SM MadGraph model. In particular, I made the following change to models/sm/couplings.py for each model:

sm_mkw/couplings.py:
GC_72 = Coupling(
    name = 'GC_72',
    value = '-((ee**2*complex(0,1)*vev)/(2.*sw**2))', # changed; added a negative sign
    order = {'QED':1}
)

sm_mkz/couplings.py:
GC_81 = Coupling(
    name = 'GC_81',
    value = '-(ee**2*complex(0,1)*vev + ... )', # changed, just added a negative sign, omitting the rest of the string for brevity
    order = {'QED':1}
)

Then, for either model, I generate 10,000 events using the following proc cards:

sm_mkw:
import model sm
import model sm_mkw
define w = w+ w-
generate p p > w h j j QCD=0

sm_mkz:
import model sm
import model sm_mkz
define w = w+ w-
generate p p > w h j j QCD=0

Importantly, I use the same seed to generate both sets of 10,000 events. This all seems to run fine, and I am left with two LHE files. What confuses me, though, is the following: there are 6,014 events that are exactly identical between the mkw and mkz samples. Now, I expect the physics to be identical on paper. However, at this step of simulation, I expect the events to either 100% identical or 0% identical (i.e. the same kinematics but not the exact same values). The fact that 60% of them are identical concerns me--perhaps I did something wrong? In case it’s helpful, I’ve put the files I used to check this here[1].

1. http://uaf-10.t2.ucsd.edu/~jguiang/dump/madgraphQuery