Using 3 different protocols/markets to help with the risks involved with volatility/manipulation is a good way to combat the risk, especially as you mentioned:
However, if you could place emphasis – more weighting – on the protocol that has the least price change would make a malicious actor have to manipulate all 3 markets.
Example:
During the DAI Liquidation Event… If Compound was getting price data from 3 sources. And adjusted weighting system, where:
Price = (Latest Price * 0.25) + (((P0 * 0.6) + (P1 * 0.3) + (P2 * 0.1)) * 0.75)
The latest price of DAI = $1.0005.
Coinbase: DAI = $1.30
Uniswap: DAI = $1.005
1inch : DAI = $1.05
Price = ($1.005 * 0.25) + ((($1.005 * 0.6) + ($1.05 * 0.3) + ($1.30 * 0.1) * 0.75)
P = $0.25125 + ($0.603 + $0.315 + $0.13) * 0.75
P = $0.25125 + ($1.048) * 0.75
P = $0.25125 + $0.786
P = $1.03725
Doing the weighting like this would make it to where a malicious actor would have to move all 3 markets. You could even drop the algorithms (less gas) you were planning on using to weight DEXs by liquidity. Even if the bad actor was able to move the largest AMM pool’s price significantly, it would have less than a 10% weight factor.
Hope I explained it right, just want to simplify the oracle while maintaining the lowest risk possible and maybe even saving a lil gas.