troopships in a campaign, ground combat

Thanks for all the discussions on troop transport requirements.  I'm
writing
up a FT strategic campaign and as just trying to figure out a simple
ground
combat and transporting of troops (think Imperium/Dark Nebula).  I came
up
with a simple ground combat but wasn't sure about the transportation. 
After
all those discussions I still don't know.

Here's what I came up with for ground combat, 1 round per Movement phase
(4 Movement phases per strategic turn, each phase 1 week long):
Roll a die for each non-neutralized (a ground unit can be neutralized by
bombardment) and add its combat factor.  Units that controlled the
planet
(defenders) get an additional +1.  For each roll of 7 or higher one
enemy 
unit is destroyed (owner of units chooses).

ground unit type	  points     combat factor
milita troops		      6 	       1
regular troops		    12		     3
drop troops		     15 	      3
armor troops		    15		     4
air squadron		     12 	    5-6 craft = 2, 3-4 craft = 1
I'm not sure about using air squadrons, but they are like a standard
fighter squadron except limited to planetside.	They can dogfight
income fighter squadrons before ground combat.

My original thought was that the size of the units was regiment or
brigade.  
Maybe they should be considered smaller? 
Cost about half as much?

Some things I haven't figured out yet:

The mass required to transport the above troops.  I wanted all the units
to require the same mass but the air squadron concept of 6 aircraft
throws it out of whack.  Maybe I should remove the air squadron?

Should I worry about landings in a strategic scale?    
   If no, just let everyone land (as long as there are no enemy FT
forces, 
such as ships or bases).   Should I require that any transports have a
certain amount of landers or streamlining?  
   If yes, then should every unit (drop troops) or lander undergo some 
sort of fire from the ground forces and how should this be done?

About bombardment, so far I have: Roll a die for every weapon system
(once per Movement phase, before ground combat) - 1-7  = no affect,
8-9  = a ground unit is neutralized, 10+ = a ground unit is destroyed
(owning player's choice).  DMs:
Beam weapons add their class,
pulse torpedoes +3,
SML +2	with +1 per salvo,
SMR +3,
ortillery +5,
a wave gun gets 2 dice with +3 per die,
a nova cannon gets 3 dice with +3 per die,
other weapon systems +0.
I don't know how Ortillery is supposed	to work in FTFB.  Currently I'm
thinking of it as its own weapons system and not attached or helping
any other weapons. 

Any suggestions are welcome.

Glen