First, let me start this post by clearning few things.
What is entrenchment; from what ive learned, it is consolidation of defensive possition. Hill, fort, plain or planet.
Now that we know this, lets move to the focal point of this: Starbase.
What is starbase? It is base so big that it can be mistaken for moon. (in before 'That is no moon!')
What purpose shuld it serve? To consolidate favorable defensive position and provide forward outpost. (plases where you can not normaly build)
Why shuld one build it? To add lots of tactical signifigance for low cost in are that you plan or allredy have held for long ---> this is realy important!
What prevents using defeses as offense in general concept? Despite low cost, long build time and inability to relocate reduces any fortification for defense and defence only. (outpost aside)
What makes defensive line worth plasing? To create line which enemy must eithr fight or find other way araund. Moving troughtit is not an option. (like Maginot line, germans didint move trought it, they moved araud it. In sins, you can run pass any defense and go ravage inner worlds.)
Thats how starbases shuld be.
How they are now
Fast consturction time. Enables them be rapidly deployed to hostile or contested area.
Inability to actualy defend anything. You have option to ignore it and do hit and run to the inner sphere.
Total lack of phase inhibitor. Star base shuld serve as whole graw well super phase inhibitor. (900% to time) Comitting any and all assault forces to fight or search way araund it.
TEC and Advent starbases immobile. This turns them into little more than glorified turrets.
Too little Hitpoints at hig levels. Fully upgradet starbase thats tiltted towards combat shuld be HARD to take down.
How to fix starbases to be more 'entrenchy' like?
Long build time. These contruction are for areas that you plan, or have alredy held long, its not some 'oh, lets just slap a big turret here' thing, its a DEATH STAR'S cousin. Starbases are the things that draw your empires border lines! Here be dragons, marzas and Siddy... and here something else!
Low cost. Constructing starbase shuld not be decision of weither gimpping your fleet or not. Long build time (10 minutes or more) will offset cheapness. Upgrades shuld be fast and expensive, since the frame is allredy up and running.
Actual use as a defensive unit. Right now starbase is a turret. Add a phase inhibitor that is more powerful than the building. Remove all enemy mines for the system were you have starbase automatically*. And scale the HP increase with upgrades properly.
Also all starbases shuld be mobile in graw well, period.
**Add the vasari starbase ability to phase betwean phase gates.
And bound the starbase to planet. So as long the starbase you build on planet X lives, you annot build new starbase on that planet. This will prevent phasing starbases in system Y and then building new from system X.
* mines shuld have an expiration time on all other graw-wells, exept the one you have starbase in - also, there shuld be maximum limit starbase can support un-expirable mines, 40 or so, all mines over the limit will expire after 5(??) or so minutes*
**maybe add this ability, the ability to phase starbase, even betwean phaaaaaaaaaasegates, will imbalance vasari defence.**
PS: Add TEC starbase ability to fuse with lvl 6 marza, creating a giant pink SPACE GUNDAM ROBOT THAT WILL RAPE YOU ALL!
And name it SUPER SPACE PAWNBOT 9001! Thats over 9000!