As far as feeding they both should do fine. When it comes to aggression, the Sailfin Blenny might be aggressive towards the Scooter Blenny, simly because it almost resembles it in color and shape. My experience is always the same, it depends on the individual fish itself. To me tha chances are 50/50, it either will be aggressive or not. It helps if you have two set of aragements of rocks, like one on each side of the tank in the long direction, with some clear space in between them. Also if you have alot of rock work, that may help in reducing the time they really see each other. The Scooter Blenny tends to be more in the open and the Sailfin Blenny tends to purch more on the rock work.Are lawnmowers Aggressive to other bottom feeders from your experience?
When it comes to eating pods it is more the Mandarin Dragonets that depend on the pods for survival. I now of some people that have been able to keep them on frozen foods though, not likely but possible.IMO a scooter blenny generally is not a good choice for a 33 gallon, or any other tank without a sump and refugium. Few dragonets accept prepared foods (at least, not without some training), and they graze almost constantly on 'pods. One dragonet can decimate your 'pod population in a matter of a couple weeks without a refugium.