Sevenstar.
The power generation differs.
Taiji uses whole body power, the whole body moves as one unit to generate power. Those are a fairly relaxed, circular and smooth movements.
Weight training tends to isolate muscle groups.
WE have weight/strength training like:
Pole shaking
Taiji Ruler
Taiji Pipe (Metal pipe filled with sand or stones)
Taiji Ball (Metal sphere size of a soccer-ball weighing 30kg)
etc.
But those are usually only trained AFTER a certain proficiency has been reached, as the taiji principles are applied to them.
Not saying that you can’t weight-train, just that to a certain degree it might be more difficult to master the art.
Power & Strength are good, but in the beginning you need to forget about them till you reached a certain level and than you can apply/use them.
Example:
We have one muscle-bound guy in our kwoon that did an external style.
It is a lot harder for him to relax and NOT rely on pure muscle strength than for people that never did strength training.
CHeers.