Unity Turn Based AI System

I'm currently building a vertical slice for a project I'm working on. I have some Unity C# experience but require help in setting up the combat prototype. If the relationship goes well there may be further work down the line on the project that I would be looking to hire for. I will provide a fuller brief of the requirements for this system but to give a rough idea what we need is: A tile grid layout in isometric view with the ability to adjust the grids size. Turn based system where the player controls one Actor, they have up to two team mates who take turns but they do no control. They can have a flexible amount of enemies. Move phase, attack phase, second action phase, allies turn, enemies turn. The grid patching system must take into account more than just the fastest route. Some tiles may have hazards or buffs and should weight themselves in such a way that AI may favour or avoid passing through them. Range and melee attacks will be catered for. This is just a prototype so we'll just be sliding different coloured cylinders around the grid and attacks will be simple animations to convey intent.