I don't draw the organisms to scale, and I agree with you LI. Lots of people are assuming that their organisms have digestive tracts, when they only have them when the stats explicitly state that they do. The original feaster was literally an acoelomate with no internal body cavity that could squirm around and ooze digestive juices onto its prey. If you never evolved new traits, then you still have these ancestral traits.
It is true that many people are trying to evolve cool, flashy evolutions, when they'd be much better served by making boring, simple evolutions. However, if no one at all is making boring, simple evolutions, then there's nothing better to outcompete the flashy, inefficient evolutions, so they'll thrive anyway. That's the funny thing about evolution- it's not about being great, it's about being good enough.
Anyway, for general sizes:
Zebedida range from about 2 cm long, to 3 meters in length.
Maves range from about 0.5 cm long, to 3 cm long.
Orata range from 0.5 cm to 15 cm long, with the Padiped being roughly the size and shape of two fists held together, thumb-to-thumb.
Curata range from 0.1 cm to 5 cm long.
Filtrara can vary massively, as many of them lack specialized tissues, so they vary from microscopic (<0.01 cm) to vast, clumped colonies. The motile descendants of the Sinker don't get bigger than a potato (15 cm diameter) while some species of Galasvi can form a large conical structure up to a meter in height and two in diameter.
Indigestibilia, being colonial, are very hard to measure in size. A single leaf may be 1-2 cm in length, while the tallest Sky-Stealers can reach a meter in height, like a small bush. In the ocean, tangled masses of Freefloater can form huge, diffuse structures filling cubic kilometers of space.
Sporida vary widely, with some Growers being microscopic algae, and others being up to 20 cm in diameter. The longest Strippers can grow up to five meters long- while they are theoretically unconstrained, biomechanical and predatory limitation usually keeps them from reaching ludicrous sizes.
Tonuda vary a great deal. The Zeppu is a marble-sized (1 cm diameter) lump of photosynthetic material attached to a 4 cm diameter balloon. Ankus, Tenkus and Prikipus can be up to 1 meter in height, the former two being lighter than air, but anchored to the ground. The remaining terrestrial plants vary from 5 cm to 2 meters in height, with Ventus and their descendants tending towards the smaller end, and Toilotils and their descendants being consistently larger.