The Warhound titan is a pig to build. Mine is still only half assembled, you have to cut the two-part pistons to size depending on the pose, it's a lot more tedious than it needs to be.
blissful this is why I bought the one made by dream forge-plastic w/screws in the joints fully posable and 1/4 the cost for a similar sized model.
Better yet play 40K in epic scale and use titanicus models.
The only problem I ever had with contemptors was in pre-assembly when I was trying to get the pose I wanted with the hips and legs, and it was a nightmare trying to hold it all together, even with blue tac. Once I started gluing, it was fine.
Rare earth magnets are the key. magnetize the joints and you have poses for days.