[BloodyButcher]

Having stationary value could be interesting, but as TheoDD pointed out the class/strength is what i would worry about.

If you want to spend value on stationary guns instead of ships, they must be favourable to ships in some way or another.
Make them too good and you could have another "Roman Fortress" round where certain planets is unlandable.
They were removed for a reason years ago, and the arguments back then might be even more valid today, as the universe is smaller and the ratio of super active/organized planets is much much higher now.