That's theory but you can keep one guy with all equipment inside the castle (safe), and then reinforcing it with equipments right after attack pop up (Raid or not). It's better to keep equipments on 1 active guy than inside fief.
Risky.
That 1 guy forgets to login for a week (internet down, computer blows up, goes on a vacation to the jungle, whatever) and you lose everything.
Similarly, you get attacked and for whatever reason he doesn't get logged in in time to reinforce, you're boned.
And even if he's alive and awake it's still better to raid. Why fight 1000 troops + 500 population when you can just fight 1000 troops? And you'll very likely get some equipment out of it.
The only downside I see to raiding is that you have to attack twice so the enemy has a chance to bring in another army from somewhere.