Welcome to the forum !
It is a ‘whole’ system and everything is important. Plus interacts with each other with dependencies that affect each other.
Length does matter, as the lever arms are longer than before. Levers for any bow wake to do it’s nasty job.
Sail area plays with length and lever arms.
Where the trailer axle is in reference to the coupler/ball makes a bigger difference than most think. this is part of the trailers architecture. Center line of the trailer axles should be behind the center of the total length of the trailer box. Some has it farther forward to reduce tongue, so lighter duty TV’s can...on paper.
Tongue (actual loaded weight) should be about >12%-15% of the total trailer weight.
The orientation of the trailer is more important, but not the only metric. Trailer should be level AFTER setting up all of the dials and knobs. Prefer pointing slightly down, but NEVER pointing up. It follows better level or pointing slightly down (after setting up).
Andersen is not a fav of mine and many report here that higher weight trailers have problems WD’ing enough weight back to the TV’s front axle. I like BlueOx, but nothing against any other, except for Andersen (that is just my preference)
WD Hitch systems are all good, IMHO. Make sure you have actual loaded, trailer weight when looking at the spring bars. The bars should be rated more than the trailer’s actual, loaded weight. How much depends on that actual weight vs what is available to you.
WD Hitch head can be tilted ‘backwards’ on some systems. That is to point the bars downwards, so that the tensioning system has more travel. Therefore able to tension the bars more.
Careful of being sent into circles dialing in one area without making sure it did’t effect another area. Just know that all the dials/knobs have an interaction with other dials and knobs.
Goal is to finish with the TV’s front axle returned to whatever your OEM’s manual says. Some say back to original Fender height before adding the tongue. Others say back within some +/- weight of original axle carrying weight BEFORE dropping the tongue on the ball.
Then that the trailer is level or pointing slightly down.
Finally, the TV’s tires must be able to handle both the weight and the push that comes from towing. That comes down to how strong the TV tires sidewalls are. Both by construction and by how much PSI vs max sidewall listed.