I think it very likely that they drive the K directly from the H.
Godlameroso suggested 50 or 60 kw for the H.
In race mode.
Car A MGU-H makes 60 kw. 2 MJ of ES can deploy the MGU-K for 33.3 secs and when the limit is reached you can still motor at ICE + 60 kw
Car B MGU-H makes 50 kw. 2 MJ of ES can deploy the MGU-K for 28.6 secs and thereafter ICE + 50.
So car A will be quicker because it can run at higher power at high speed at the end of straights.
However there is another way to extract the advantage.
At most circuits they can only recover about 1 mJ under braking. So they have to burn fuel to charge further. They have 2 methods.
At part throttle they run against the K charging the ES at 120 kw. Depending how good the H is they may supplement this with excess power from the H.
At full throttle they divert H power from K to the ES
To extract the advantage in the example above you charge the ES to 2 mJ. However you could also charge the ES to less than 2 mJ, burn less fuel and so start with a lighter car. So now a car with a superior H, car A, can still match the deployment duration of car B but corner faster and accelerate more quickly. This may well be more effective than longer deployment.
Potentially there is some positive feedback when all you are trying to do is match lap times. Now car A can reduce the ES charge still further use less fuel, run lighter etc.
I don’t imagine there is a 10 kw difference between the engines but this mechanism would amplify any superiority in H output and lead to a significant difference in starting fuel loads.


