Assume for a moment that whatever "Game Balance" is, it doesn't matter. Think about people who have two careers at the same time. For example, an Navy Reservist who is a Bureaucrat in a Civil Service Bureaucracy. Or a Marine entrepreneur who is a Merchant on the side. 
While there are only so many hours in any given time span, let's use two simple measures.
A) The character is in one Career mainly, the other only in name. For example, a Navy Officer with a Soc B+ who just attends parties now and again.
B) The character works both careers equally. This is the Marine who runs his business late into the evenings, on weekends, and attends classes to get his MBA.
In the case of A, chargen is simply for the primary career and the secondary is noted.
In the case of B the character can get a few more options. In CT LBB 1-3 they get 2 skills per term, plus any for commission, promotion, etc. Some careers have default skills. So, the character could get something like this:
Default skills as noted.
Commission and Promotion skills from that Career's tables.
General skill advances from either set of tables.
Muster out uses any available tables. Maximum number of Cash rolls applies period, rank or term adjustments reflect on that career for that career's tables.
If you are using LBB 4-8 then perhaps a better way would be to run each term in one career. Muster out as above.
What did I miss?
				
			While there are only so many hours in any given time span, let's use two simple measures.
A) The character is in one Career mainly, the other only in name. For example, a Navy Officer with a Soc B+ who just attends parties now and again.
B) The character works both careers equally. This is the Marine who runs his business late into the evenings, on weekends, and attends classes to get his MBA.
In the case of A, chargen is simply for the primary career and the secondary is noted.
In the case of B the character can get a few more options. In CT LBB 1-3 they get 2 skills per term, plus any for commission, promotion, etc. Some careers have default skills. So, the character could get something like this:
Default skills as noted.
Commission and Promotion skills from that Career's tables.
General skill advances from either set of tables.
Muster out uses any available tables. Maximum number of Cash rolls applies period, rank or term adjustments reflect on that career for that career's tables.
If you are using LBB 4-8 then perhaps a better way would be to run each term in one career. Muster out as above.
What did I miss?