I've said this before, but how a decision based on looks leaves you keeping Garrett Wang and sacking Jennifer Lien baffles me.
They wanted to put Seven of Nine on the show and budjet wouldn't pay for both.
You remember how the budget used to allow for Seska and Kulluh and all their minions? That was a second tier of actors and some additional permanent sets....
Berman scrapped all that to increase their cgi budget.
If they wanted to keep Jennifer, or more accurately "Get Jeri" then all they had to do is reduce the cgi budget back to where it was in seaosn 2, or at least what it was adjusted for inflation.