i think more realistic at the end it will be that 1 crawler gives you 0,036% something must be wrong in this formula. It is pointless to have 150 crawlers, no problem for defense, no problem for energy... simply you can give anyone 30% boost instead of crawlers.
If a fleeter have 1600+ crawlers and everytime has to buy them in the marketplace cause someone bash him often, will you like it anyway? Even if you are the one attacked often
I am more worried because I am a miner. As a fleeter I would have 2500 crawlers with no problem on my planets with very small defense or maybe even zero. You need to have pretty big balls to attack fleeter. Attacking miners on the other way is pussy move in my point of view. We are not and we don't want to do any dmg to anyone. I was a fleeter for more than 5 years and I did not attack single planet for defense bashing or taking a small profit from there.