looks like a good start. fitting existing parts over the frame of another figure like your doing here is a real challenge.
how did you fit the chest over the Blanx figure? did you hollow it out to fit over it?
that tiny waist looks even more anorexic now though
You should add some pouches or even sculpt it up to match the waist and chest armor for a more flush look.
You did an excellent job on the legs though. I'm assuming the thigh armor is slipped over the Blanx thigh and then the boots are joined by cutting off the feet of the blanx figure and transplanting over the feet and boots of the kashyyyk trooper? If you do it just right that might add the needed height to boost this figure up to the correct sccale to fit with other figure lines.