The market maker over an exchange tends not to engage in what you mention. That is not in the exchanges best interest. They want to provide the liquidity to people keep using the exchange.

What you are referring to is those bots that put in a wall of buy orders (fake) in an effort to draw others buyers in to sell to them and the reverse on the sell side. These tend not to be the exchange market makers like @aggroed is talking about. It is not in Steem Engines best interest to have its bot manipulating pricing since that would cause people to leave the exchange.

The manipulation would come from someone making their own bot and using it on Steem Engine. If you are I did that, then we could manipulate (attempt to) the pricing on different tokens to our advantage. And if we had enough capital behind us, we could affect the liquidity by the ebb and flow of our actions.