[Collector]

All this does is heightens the bar required to quickly clear content, thus making it more difficult for casual people to reach content.

At the highest level, the fastest grind is 4 people all with good builds. Mercenaries are turned off for that as they just take slow turns when you could have 4 rounds of quaking steps on a back attacked/boar bear trapped enemy group.

This is just... incorrect.

The fastest, most efficient grind setups don't use mercs at all, like you said, but are done ALONE. Things tend to go more quickly when only ONE person has to take their turn; especially with grinder builds.

Casual players can reach content perfectly fine with the proposed mercs, they just won't be carried by them.

Also, casual players starting from zero don't have the ability to capture high-level mercenaries. If someone were to HELP them, they might, but players are still able to help them with the proposed changes.