I know that while in a clan, some one asks if there defense set up is good. It is difficult explaining to someone why they may need to change something. Or if you are wondering if they way you have things set up are better or not. So I think it might be a good idea to add a feature to test your own and a clan members war and/or normal town defenses when they give a request for it ( so not to bombard one another with notifications and such). You do not lose troops by testing someone's defenses because that would cost way too much, you just set up troops and use them to test (and keep them) then use those same troops to raid or donate or whatever. After the test you get the video (for yourself) or the person's town you were testing get the video and they see what they should fix.
