Almost all of bars are hard to read, they're either rather busy or all blend together and don't give good info. I find myself counting those tiny highlights to count them because that's the only thing I can see distinctly, but it's unpleasant.
I mentioned bars with variable-length segments before as something I dislike because I find it hurts the player's ability to read the health at a glance. That's fine in a game where a single HP isn't like to mean life and death, but in a game like this, I find it important to be able to tell how much HP exactly a character has without counting the bars, and that's a lot easier if each HP is represented by identical, same-sized visuals across all characters.
That's true. Segmented bars probably wouldn't work here.
How will these health bars interact with units in front of them? I thought you mentioned that as a reason not to have health displayed under/over the units before.
That's before I realized... I need to display the health of enemies as well. I can display the information for players on the left side, sure, but what about the enemies? I don't want the players to have to select each enemy to find out how much health he has. That'd be stupid.
So I did some research and as it turns out, most games don't display the characters info on the action screen!:
Battle Ogre:
Final Fantasy Tactics:
Suikoden Tactics:

Disgaea is different as it displays the health as a bar, nothing precise.

I find Disgaea is superior in that aspect since you don't have to select a character to know its health.
So how about this:
The token gradually gets filled up with semi-transparent red as they're wounded. It wouldn't be super precise *but* it would give an idea to the player who could then go and check the precise health of the token he's interested into for gameplay reasons.
Something like this:

(uninjured)

(injured)
I feel like that'd be a good compromise. Moving the cursor to a selected token would then display the full information in the text area at the bottom for the player to see. Another solution would be to press a button for the health of everyone be displayed as numbers on top of the tokens as long as that button is pressed for quick info.
Regarding character sheet, I'm coming to terms that I'll need to use numbers for reasons both practical and aesthetic.
Aesthetic: wasted space. I end up with a lot of empty space because I need room in case the player improves his stats.

Pragmatic:
*There's also the point that was mentioned that certain stats can't go higher because there's no room on the sheet, like for the dwarf's health.
*There's also the problem of counting units which, like eishiya said, ends up being problematic. That can work for certain games but for something like tactical battle, it would become a chore to count little icons.
*Dealing with half units is bothersome. The wizard having only 2 health would cause trouble with grazing. If the smallest unit is half a heart, it still wouldn't take much for him to die. Low health also means instant kill which players likely won't enjoy.
I could of course use mechanics where damage taken is minimal but then it becomes a headache to factor in equipment see I have little to no room for stat variety.
So I'll have to switch to numbers. This will allow me to use my space more effectively, have player know instantly the info they're looking for and more freedom with combat design. I will want to keep numbers low however, there's a charm to it. I feel that using numbers breaks immersion more than icons for some reason as you go from graphical representation to numerical but that's unavoidable at that point.
Using bars for health would be overkill in that case though I find:

I think I'll just stick to numbers.