I have the same issue with my boys. Toby is absolutely obsessed with food, but Havoc is a dainty eater who is easily distracted away from the food bowl. Havoc was pretty scrawny when I brought him home, so I fed him more often. This drove Toby bonkers and I had to sit with Havoc until the second he got tired of eating, otherwise Toby would swoop in like a vulture and inhale the food before Havoc had even fully turned around to leave. I ended up giving Toby just a little bit of food whenever I gave Havoc a snack and adjusting the amount Toby got for his official dinner. Havoc finally filled out and I don't feed him any extra times, but I still have to sit with him while he eats. Toby isn't as quick to grab the leftovers as he used to be, but he'll still clean out an unattended bowl as soon as he's sure the coast is clear.

Tiny may just be a finicky eater or easily distracted by the other cats' over-reaction to feeding time. I would suggest trying to find a food he really enjoys, if only so he eats more of it at once. Also I would either put him or the other kitties in another room until Tiny has had ample time to eat as much as he wants.