It’s not really a matter of “which engine is better” because that’s all code that you will be creating yourself.
Personally, I’m developing a turn-based strategy in UE4. At a fundamental level, all you need to do is restrict certain types of input at certain times.
-1- If the current player isn’t this player: Only let them move their camera.
-2- If the current player is this player, but they haven’t selected a unit: Let them move the camera and select something (move to -3-).
-3- If the current player is this player, and they have selected a unit: Let them move the camera and select a place to move (move to -4-) OR select a different piece (stay at -3-).
-4- Lock the player camera, perform the animations, unlock the camera, and increment current player, modulo number of players. (This implicitly moves to -1-.)
The game itself is real-time. Time moves on at a regular interval. A turn-based game only locks game-affecting input when it’s not a player’s turn. Again, the engine thinks everything is real time. You are just using a manager class (your GameMode subclass itself or helper object/actor) to only listen to certain things at certain times.
Note: If all players move simultaneously, you would lock the game-affecting input after the player confirms their turn until the turn ends. There’s many subtle differences between turn-based strategies. It all depends on what you had in mind.