Hi, if anyone wants to search these up the jousting knights the key item is called "horse coat" at PlaymoDB.
Here are the known set numbers for the ones you mention:
14 - sets 3319 and 5757, 3319 was a release troop builder so should be out there
20 - 7762 an add on accessories set, general release but harder to find
25 - 4160 an Advent calendar
27 - 4865 a large castle set, bigger castles are released in smaller numbers and finding the one thing without having to get a castle or a ton of random parts with it may be hard
28 - 4871 a troop builder set, should be pretty available
