IMO no absolutely not.
They are bred to pull not ride,they are not agile,they weigh up to a ton which is a lot of concussion upon landing,and then there is the hock issue as you say.
Clydes are also bred to be cow hocked (not sure about shires,but think they might be as well),I am assuming that although it makes them neat for stepping onto the furrows for ploughing,it might not be so great for being straight moving for any riding activity let alone jumping.
I'm not certain about that BTW,but it stands to reason that what would basically be considered a conformation fault in any other breed might well affect way of going and strength and longevity of the joint.
I have owned a heavy as many of you will remember,so I don't express this opinion through ignorance and assumption.That's not to say it has any merit and it is of course only my opinion.Personally though I don't think heavies are suitable build wise for jumping.
They can jump obviously,and perhaps for some of the lighter built ones small occasional jumping won't be too detrimental,but I never let anyone jump my girl when I had her.
I don't think they make the best all round riding horses full stop TBH.Not agile enough and a devil to keep fully fit for the work.Fine for a safe hack and perhaps low level activities (not jumping though) or even higher level *if* ensure they have enough space to move properly (pet hate of mine seeing heavy horses being worked in small schooling areas,too difficult for them and hard on the joints),and are kept fit and supple appropriately.
Agree with what said above really,if you want a horse that can do all activities,buy one suitable for purpose.You wouldn't buy a TB to pull a cart,why buy a carthorse for jumping??
*disclaimer* I am not generalising about ALL heavies,some are lighter built and modern bred to do different jobs now,I am also not referring to cross breeds,they are often very suitable for all activities.I am meaning proper heavy horses that are true to type and their original purpose.