I have a gripe that has been bothering me since I first started playing this game and maybe someone can help me with this.

Ever since i was an earlier level to my current castle level 21 and hero level 43, when I attack castles I don't get the same amount of resources other castle get when they attack me.

For instance i was attacked today and someone took 1.5 mil food and 1 mil gold in ONE attack.
However when I attacked 3 other of  his teammates the most I took was 400k gold in one go.  No other resources.  One of the castles was only level 15 as well.

I have noticed this from the beginning when I am attacked almost all my gold is wiped out in one go, and my resources are pushed to vault limits.  However for me when I attack and my army is close too 200k I can still only get a couple hundred thousand and i don't deplete multiple resources at one time. 

Meanwhile my food, stone, wood and gold can all go in one attack.  I thought as I got stronger it would change but it hasn't.

What determines how much you get when you attack someone?  If i'm overwhelmingly stronger why can't I deplete large amounts of gold like when i get attacked?  These are not level 24 or 25 castles mind you. I'm talking anyone castle 23 and under when I attack I get pennies for my efforts can someone assist me with this because its maddening.

There are so much we have to take in account with your case, for example: 

- how much attacker had troops in one attack. The more you have troops, the more you can steal resources from player.

- Did you have troops to defending? that could also affect the amount of resources he can steal from you. Im not sure. 

- What kind of troops he used. T1, T2, T3 or T4. You can loot more resources with higher tier troops.

- Army max load % could also affect how much you can loot. 

When it comes to your attacks, enemy could have upgraded admin researches and therefore you cant loot as much resources from him as hes research is protecting most of hes resources. 

I dont personally really care how much I can loot from players. I can always do 1-3 attacks to enemy castle. On top of that, I get higher winrate (I know, some people are not into this, haha). Thats why I cant give you more information regarding your question as I havent really paid, that much attention how much I can steal resources. I just enjoy to see those sweet castles burning 

The game is still quite new, give it time. Eventually players have alot more information about the game and means there will be alot more guides on youtube and forums.

Thank you.  I don't know my army is pretty big.  I hit people and i don't take as much resources as they take from me.  It's super annoying lol.

But lol @ sweet castles burning.

You also have to consider if the person your attacking gave resources away.

One way to hide or protect excess resources (or even troops) would be to give them to a shielded guildmate or simply don't keep resources that are too far above your vault's level.

So if your vault can hold 1,000,000 resources and you keep no more than 1,100,000 resources on hand the most someone can take is 100,000 vice versa if you kept 2,000,000 resources with that same example someone "could" potential take 1million resources from you depending on their attacking army. And in both of those cases above another way to lessen the blow is to simply send it to someone else on a regular basis.

I would guess that's what your seeing and its a very common practice lately.