You need to look at the cleaning crew as a dynamic number. A tank that has a lot of algae will require a lot of algae eating animals. A tank that has no algae - much less.
The best algae eating animal there is so far is the Amano shrimp. They can handle virtually all types of algae (including Cladophora and BBA) IF the number of shrimp corresponds to the algae infestation.
Here's an example, from personal observation:
200 Amano shrimp in a 25 gallon tank will completely eat a Cladophora mat that is 2" thick in about 3-4 days.
Of course stuffing 200 Amanos in a 25 gallon tank is a pretty ugly sight. It's also crazy to put so many animals in such small volume. We import rare fish and shrimp so we take great care of the tanks. It takes a lot of effort to maintain so many animals in such a small volume. But my point is that it seems that no algae is safe if the number of algae eating animals is appropriate.
Otos and SAEs are "old school" algae eaters. They are not very effective. Look for the newly imported gobies, Red Lizards, Neritina snails, and Garras. Stiphodon and Syciopterus are the genuses of the gobies that will eat dust algae and BBA.