The Psion class and the Summoner class appear to be well thought out implementations of these concepts. As an example, while the summoner has access to powerful summons and the ability to enhance the abilities of summoned creatures, significant restrictions on spellcasting while controlling a summoned creature, as well as action economy restrictions limit the power of the summons. The summoner can have two active summons, and can use their action to command both summoned creatures to take actions from their stat blocks. At 11th level, this can be done as a bonus action, but at the cost of gaining a point of exhaustion.