So get rid of the "only one reaction per turn" limitation. Let characters use as many reactions as they have different types of reaction available, but only let each category trigger once.
So, your basic Opportunity Attack triggers on the first enemy to leave your threat range. Your Shield spell triggers the first time you're hit by an attack that would have missed with Shield activated. Etc.
I would prefer that these are under the player's control. I would also prefer to have square by square movement as well. It is one of the things that bugs me the most with X-Com and other turn-based games is they don't let you use your movement to its fullest.
In fact the whole point of having a turn-based game is to allow fine control of movement and reactions.
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The problem with RTwP is combat is either face-rolling your way through it or pausing so much that it becomes more tedious than turn-based.
For example, in Kingmaker one can face-roll though 90% of the combats in the game. The reason is that the nature of the encounters and the limited spells make only certain parties really viable. In the first part of the game, the most difficult encounter is with spider swarms since the party doesn't have a really good method of countering them. However, once you understand how to fight them, it also become fairly simple.
To faceroll through the game you build a party that is composed of: an elven druid with a bear companion, a rogue, and 4 fighters. Give everyone a bow. Have the bear companion tank all of the fights and everyone else just gun down the opposition. For the few times you get surrounded, make sure all of your fighters have maxed their AC and are using sword and shield. Have one or two start tanking if necessary. Target enemy spellcasters first with bows (obviously) as you can completely shut them down as they never cast protection from arrows. The rogue is for opening chests and handling traps -- plus sneak attack damage with the bow is awesome. The rogue provides the stealth while camping, the druid provides the hunting, one character (the main) should focus on world knowledge and the rest on perception.
In fact, to do the extended finale they completely nerf spell casters, so taking a wizard, sorcerer, magus, cleric, etc. is pointless. There is a ton of healing in the game, but if necessary, have one character multiclass into cleric to provide some minimal healing. There are a ton of condition removal potions in the game as well. And if that isn't enough, you still get the NPC clerics that can be swapped into the party just for that purpose.
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This is pretty much how all RTwP games work anyway. The Baldur's Gate series didn't really reward character diversity either. Bows reigned supreme in the first game. They did become less useful in the second, but then you just dual classed your fighters into wizards for the second and took care of it that way.
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If someone wants a D&D inspired game I suggest the Neverwinter MMO. It is D&D inspired -- also boring AF. I made it to level 30 when you get your big bonus. What a yawn fest. Tactical options just about nil. Just spam the same three abilities over and over. Skyrim has way more tactical depth.
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The other problem with these games is that the main character has to carry all of the dialogue so by definition also has to be a face character. The only game in which I think that was party based that this was done correctly, IMHO, was Neverwinter Nights 2: Storms of Zehir. In this game none of the characters was the "main". All characters were equal in the party. Unfortunately, by the time SoZ came out, I think most people had moved on and had stopped playing. However, SoZ should have been what they led with as it had a number of innovative systems that any game developer should take a hard look at.