Combat Speed should determine who goes first in tactical combat, not who attacked.  Work your way down from highest combat speed to lowest combat speed, instead of "all attackers first, then all defenders".  Don't let us switch units in tactical combat; force us to use the unit who's turn it is.  As movement points are used, the number of MP drops, and the unit with the next highest MP availability moves until they drop below some other unit, and so on, until all moves are spent.  THen click end turn, and reset all the MP (attacker and defender) at once.  If you want a little randomization in the combat order, make a +/- 20% on MP to each unit each turn at random.

Let me have multiple attacks from even a simple club wielder: a quick feint that does low damage, but consumes little MP, or an overhead swing, which can deal massive damage, but costs all my MP.

Magic should always hit.  Always, always, always.  And it should always hit for A LOT.

Give me more points to spend on level up; like 3 per, with each one raising a stat 1 point (maybe it raises essence 2).  Let me craft different characters out of my champions.

When I hire a new hero, let me pick their spellbooks then, from what I know when I imbue them.  Don't make all my heros have the same spellbook, which is mine; they should have subsets of my spellbook.

Let me have a spell that affects diplomacy, by raising my standing with an opposing faction.  Also, let me have a spell that lowers someone else's standing with a third party, so I can use magic to invoke a war.

Give me stealth, as an item, for normal units, like the ranger pack.  Also, give me stealth as a spell.

Let me imbue spells (yes, costing me essence) into items for regular units.  I want to imbue this crystal crag with healing, so I can make rings that let a set of units cast healing.  Imbue a crag once, and it's focussed on that spell.  Yes, it will make it a separate resource (crystals of healing, or what have you).  Crystal crags that are unimbued are used for generic +atk (for weapons) or +def (for armor).

Let me make magical armor and weapons for normal units,  Let me do that early enough in the game so that it's strategic (yes, I'm aware there are magical armors and weapons in the game.  I don't want a ring or amulet, those are for heroes, not troops).

Make crystal crags more common.  This is a world where magic was once common.  Crags (and shards) are the only magical resources currently in game.

Give me some way to put special attacks or moves on normal units.  When my axemen level up, give me access to an alternate special attack (see above on different attack modes).

Increase mana regen in the field, or give me a low to mid level building (not the tower) that increases it.

Again, just thoughts.  Winni