I looked at those mini movies from the playlist and found some connection between a few of them.
Black Widow,
Hulk goes shopping and
Captain America and Thor playing ball all follow after each other in that order because at the end there is a black and white image of a scene from the next animation (e.g. black widow ends with the shop that hulk goes into). The transition from the black widow short and hulk short is that there is the image and also a shake/bang sound that is at the end of the black widow short and during the hulk short. The same goes for hulk short with a black and white photo of the cap/thor short and both characters going to/looking at avengers tower at the end of their shorts.
Placing this on the timeline, they seem to take place just before the start of avengers reassembled because they released the same year (before) reassembled and all the characters have similar or the same outfit to the reassembled ones. They also all rush to avengers tower to most likely help set up the party at the start of reassembled, which explains why hulk is buying a glass.
You don't have to add this to your timeline but if you do I would order it like this:
-Black Widow at lunch time
-Hulk goes shopping
-Captain America and Thor play ball
-Avengers Reassembled
