Garthanos
Arcadian Knight
I actually see minions and swarms as fighting styles in reaction to the situation the same Ogre against level 4 schlubs will be knocking people around with his bad assed moves that 5e never gives him btw (in story the same ogre and same moves just lack the omph to do anything much they have to adjust taking easier opening trying to risk less and failing resoundingly)However, I have never heard complaints about minions. Ever. And I'm a huge 4E fan and I've very personally gotten heat for that. But minions? Eh. Never heard those complaints. Honest truth, never heard anyone complain about minions. Generally speaking even among 4E haters, what 4E did for monsters is usually regarded positively.
Minions are out of their league and they know it easily intimidated I consider them functionally always bloodied, they lash out out with desperate attacks which leave them open to retaliation and scramble with similarly exaggerated attempts that only stop the least of attacks while still leaving deadly openings they are in their present context the delta on the totem pole they generally look to leaders or are bullied or inspired by leaders into being in this circumstance when they would rather be elsewhere.
Yes same monster fighting differently when outclassed and forced to.
The swarm is a group acting much more in concert as individuals the probably would be minions but training and team work and the presence of a leader make all the difference when a swarm is defeated you may have stragglers of minions but the majority are not necessarily killed but usually rather dispersed (rather like armies where it was historically rare for a war to average 1/4 dead)
I have heard someone also call minions a tacit allowance for the Trope of "conservation of Ninjutsu" - which is kind of fun