mostly kill NPC's , so size doesnt realy matter mutch to me
so ad as many decks as I need to get all the NPC/mission systems I pick up online

Rank 847 - 5334 Decks
Player Kills 1.157 vs Non-Player Kills 57.401

tldr only read the title answer: yes

very general question in OP

1) depends on the rank and base production
2) depends on player orientation to PvE or missions
3) depends how you get planets - scanning on your own or buying them/legion alerts
4) why nobody expect a change in ship built?

Till rank 100 LSB on research base while strong PVP to gain 4 Doms III, then moved to MSB on arti base mostly.
Long way to go to 1200 decks.

The only modules I swap in and out are the researched scan and researched attack mods. Typically I scan less than once a month, so making permanent room for all the scan modules isn't a big gain in convenience, and the drop of a couple hundred points on my damage cap seems like a day to day gain.