If uke's structure is better, no angle will change the outcome -- it won't work. Resistance is for those who don't have good structure, and if they don't have good structure, then kotegaeshi will work. Changing an angle is just jujutsu. yeah, it'll work for those resisting (see above sentence). But come into contact with someone who has structure and angles don't matter.

Reread Ellis Amdur's post here on AikiWeb about Tomiki holding his hand out to judo players. No amount of angles will work on someone who has structure, or as some people call it -- aiki.

Want to make kotegaeshi work with resistance -- work on having better structure/aiki.