A point on the equalizer bar on a multi axle trailer.
One point is they function to let the trailers suspension step through/over a obstacle with out one tire taking all of the weight.
They will not equalize weight between the axles equally. As one poster mentions a trailer with a high front can overload the trailers rear axle which unloads the front axles.
I'm on some type of scales weekly with a 36' tri axle stock trailer and have seen the results of a nose high trailer in most cases. Many RVers and farmers/ranchers use a 4x4 truck which can cause the trailer to be nose high and overload the trailers rear axle. I've seen scale tickets for a 6k tandem axle trailer with 6600 lbs on the rear axle and 5600 on the front axle all from a nose high trailer sitting on a 4x4 Dtruck.
Also much depends on the trailers length IE; distance from the pin to of the axle systems.