Most of the work is in Maya, the Eaglemoss ones are made off of lightwave, You can do model conversion, actually quite easily.. As a person who uses these programs, its realitivly easy to import the base model into a new program. However.. when it comes to the textures it could be a mess, and then your dealing with a model that was made with very little detail.. so some clean up and re texturing is a minimum.. and sometimes that can take longer than starting from scratch...
Even if they got it from eaglemoss, still would have to import it, clean it up, re texture, re LIGHT it.. take a few days atleast.
So i go to my original thought..
No budget to make new ships, not given time ( which costs money) so they just used something that was screen ready like the ship, the tug, the work bees, hell even the dock.. Now us looking at it.. Yes.. they should have tossed a few days worth of money for a few guys/girls/they/shen to put a new (old) ship in.
No new Tng and forward stuff has been on tv/movie since 2004 ( ending of the garbage Enterprise Seres finale) with the Ent D. so no Akira, no voyager, no promethius.. nothing, with a thought of.. Can they even find it??