He seems to be hard, but only if you haven't done an analysis at the start. All what you need is known from the beginning. You know the amount of materials and gold which is needed, in which order it is to send and so what amounts can be pre-delivered. You know the amount of the needed mats in your storage. You should know your fleet-size for each material. You know how many fleets you are able to send out in the given time-frame. Based on this informations, he is impossible, if you don't have all materials in your storage - maybe levels 1000+ are able to collect one or two missing materials you have 28 days, so multiply with the times you send out your IT fleet, say 3 times/day, so you have 84 runs: if your fleet-size isn't greater than 1M per material, it will get hard, you have to use IT-speed-ups to catch up.