There are two reasons to go small after you get a big fleet:
* "Operating costs" - mainly if I shop or explore in a system... or if bounties outlevel my fleet and I need a two frigate fleet to do missions.
* Transferring ships from one stash to another (because you cannot transfer ships if you have too many).
Since player can build colonies and using others' storage will cost money, player will probably consolidate his holdings as soon as possible, instead of scattering them across the sector.
Re: Foof's post
We used to have something similar with Logistics in the 0.6 era. Only problem, pre-0.65, you need an Atlas fleet to have enough capacity to loot endgame fleets without overflow. In 0.65, you had food runs dominating income, best exploited by 15+ Atlas fleet with one or two Hyperion soloing endgame fleets (and that will take more than 100 Logistics). If you want to fight (bounties on the side) with a full-blown combat fleet, it was better to deploy all, destroy enemy instantly, and stand down to recover half CR (because you curbstomped enemy fast with overwhelming force). Frigate swarms exploited this best, and they were much faster than every other (otherwise viable) fleet. Bottom line, huge fleets were optimal because they maximized profit of 0.6x cash cows.
And because cleaning out markets (to force more new monthly stock) is expensive, there was no such thing as too much money. It was like using a gold-find character in Diablo II to grind for gold and gamble it all away with a few clicks at Gheed's for a chance of a unique or good rare (or high level specialty item).
0.7 did away with food runs, killer frigate swarms, and... Logistics (and by extension, efficiency bonuses).
Maybe small fleet efficiency bonuses, determined by character level, can make a comeback since the 0.6 era cash cows are gone.
Re: Goumindong 's post
Interdiction is... clunky. Player probably wants Sustained Burn. Using interdiction turns off SB and kills your speed. If the enemy was faster than you (and it will if you have Prometheus in your fleet), you either need SB or EB to close the distance. EB costs too much, and turning on SB delays your fleet enough that enemy recovers and you are back to square one. So far, Interdiction is only useful (to you) to cause a persistent pursuer (with EB or SB on) to back off from your fleet (because they run away), not to catch the fleet you want to kill. Addition of Interdiction mostly gave AI another tool to grief or troll the player, usually non-hostiles getting in your way.
Bounty fleets? Sustained Burn outspeeds them, and if you need a bit more agility, toggle it off, redirect, toggle it on.
Stealth and smuggling? Just rush to the planet with SB on and pray. Sometimes, the patrols are away or distracted, and your huge fleet of capitals and superfreighters make it, and you can do whatever. When I try to sneak with a small but slow fleet, what happens is one among 1) faster patrol wanders unaware toward my fleet and it is hard to get out of the way, 2) patrol pings sensor burst and my stealth is blown, 3) too many patrols crowd around planet and fleet size does not matter, better to come with big fleet and destroy them, 4) I make it... and my capacity is not enough to fully take advantage of deals; wished I brought Atlas and/or Prometheus with me.
And I have no problem with Sustained Burn dominating travel, since player can use whatever ships he wants, instead of the frigate swarm of doom. The only time Sustained Burn is a liability is which I need to push through solar wind to reach a pinata in space, like research station inside a star's corona.