Very High Level
Okay, I'm going to try to ignore analysis, and think of Traveller squadron combat on a 3' x 4' hexmat with a couple dozen units on a side, played to completion in an hour's time.
I think:
There would be about twenty turns. Turns phase as follows:
(1) The players choose the units to order, and choose an order for each of those units.
(2) The choice of units and the order for each unit is then revealed.
(3) Order resolution is not simultaneous: initiative decides which unit acts first. Actions of the phasing unit may block the actions of later units -- for example, if your cruiser goes first and its PA spine destroys my dreadnought, then that dreadnought does not execute its orders.
No Really, What is Combat Like?
Ok, all of that pussyfooting above is just me stalling because figuring out how actual batteries fire on targets, and how the defender defends himself, and how damage is inflicted, and how damage is tracked, intimidates me.
Assume two players: Ixtalpox the droyne and Oukloe the vargr.
Ixtalpox may give two orders. He orders forward his dreadnought and a "group unit" of four escorts (perhaps specifically formed into a group in a previous move, or perhaps a characteristic inherent to escorts) in an attempt to seize control of the center of the mat, prime real estate and a threat to the mainworld, which is in the center of the eastern third of the map. The escorts are by default in "screen" mode specifically around the dreadnought. His other dreadnoughts each have their own team of four escorts, by default also operating in "screen" mode.
Meanwhile, Oukloe may give three orders. She has directed three of her "silent" "suicide" monitors, stationed behind the invading fleet, to strike behind the rearmost dreadnought, where its spine cannot be brought to bear against them.
The monitors have an exceedingly high initiative, so their attack happens before Ixtalpox moves his units. Their spinal weapons attack at long range, but are powerful, and the spinal attacks score strafing hits. The dreadnought's defenses then kick in, and the first line of defense is the escort group unit which is "screening" the dreadnought. The strafing hit from Monitor No. 1 annihilates Escort No. 1, continues on and tactically kills Escort No. 2. The strafing hit from Monitor No. 2 is a glance and fails to damage Escort No. 3. The strafing hit from Monitor No. 3. tactically kills Escort No. 4.
Ixtalpox' dreadnought and escort screen then takes the center of the map with no resistance.
The turn ends with Ixtalpox in nominal control of the center of the map, and his rearmost dreadnought threatened by three of Oukloe's "suicide monitors".
Initiative Helps You How?
1. The player with initiative attacks first.
2. Then the other guy attacks.
3. Then the other guy moves.
4. Then the player with initiative moves.
This ASSUMES:
1. If your attack kills a unit, it then cannot attack or move, starting immediately.
2. You have some degree of freedom to choose how to move a unit, i.e. ordering a unit to move may not imply a route.
So Many Units, So Little Time
With two dozen units, you can't just order around two units at a time (for example). It would take forever to build a formation or stage an assault. But more than four orders per turn becomes unwieldy.
One way to handle this is to allow units to form into a Task Force. Each side could then make grander moves when they need to move the squadron, and then settle into surgical moves and attacks when in position. Escort-class vessels, whose primary function is screening, may have the special ability to form into their own Task Force without expending an Order.
So in the scenario above, Ixtalpox may instead issue one order to form a "Task Force" of his entire squadron, then issue a second order to "move forward", i.e. the attempt to possess the center of the mat. If he did this, Oukloe's monitors would still attack, having initiative and getting to fire first, but then the entire squadron would pick up and move away from them, dulling their future usefulness.