S-S-S-SUGGESTION DOUBLE POST:
I would suggest a system be put in place similar to the supports found in FEF. I think it's a fantastic mechanic, and here are some reasons why:
1. It encourages RP, both intra- and inter-personal.
Support or similar systems are excellent for RP and characterization. For example, as you know, I play Alexander Jorinn in FEF. A lot of his character was forged from support talks, or talks that could have become support talks. It aids very well establishes bonds between characters, so for example the group of medieval warriors and mages seeking to overthrow the evil lady of the land, you have a tight group of friends- and some more than friends- with backstories that are shared with each other. Now, you may say, supports aren't needed for that kind of thing, but since they provide stat bonuses, they provide distinct incentives for roleplay.
2. It leads to interesting strategies and behaviors on the battlefield.
For example, say a spearman-tank and a archer-glass cannon have a support (greglottttte). Are they going to spread around and switch positions randomly more often than otherwise? No. They might make a strategy involving the two specific characters, keeping the army of characters arranged in an interally consistent arrangement. And it leads to ways of non-linear thinking- Alexander, for example, managed to do a pacifist run of a mission because his build is built around supports and guarding them.
3. It provides an interesting stat addition or other things
Stat additions borne of supports could do two things stat-wise to make the game much more fun- they could provide mostly unused stats, to help specialized builds not get stuck in ruts when their skills are less useless, or to further ridiculously minmax a class. But it doesn't have to be a stat addition. Suppose, for example, that characters with supports could get abilities that fused some of their abilities- a teleportation mage and a healer, for example, could gain an ability that allowed them to retreat and heal by using both of their actions. That would allow for fun combinations of how classes work.
4. It doesn't take a whole ton of effort to upkeep, esp if used with abilities as I previously suggested.
Unlike many abilities, supports don't have a whole ton of conditions to check for, and they're relatively simple to set up- as you only have to check if they're near each other. And you could do it on your own pace, choosing when you think someone RPs with another well enough to get a support, without having to synch it with the level up system. If used with the ability system, you would only ever have to check when two people use an active ability together, or as it is in FEF with passive abilities.
5. The OOC shenanigans.
Admit it. Shipping from supports, and the OOC shenanigans that result, are absolutely hilarious.