i have question about the plan. i am not sure how to make the electric wiring diagram for that for internal battery and internal cable/wiring

i will change gears by
2x sw-r600 (l/r)
2x sw-671 (l/r)

those 4 cables get joined in a sm-ew90b

which get forwarded by a cable to a sm-ew-67-a-e

which get forwarded by a cable to an sm-jc41

from this sm-jc41

one cable goes to sm-btr2
one cable to fd-6770
one cable to rd-6770

and thats it? or were is my flaw in the plan?

thanks!

(yes not brake levers, they are non-shimano)