I like the RNG, it has no negative effect you can only get better ships out of it. Also the people with lots of resources will spend them and sell the ships with traits they do not want giving the less rich of the server cheaper ships. Without the RNG in crafting people generally only craft the ship they need and no more leading to no players selling ships.
Side note, building ships outside the reinforce zone allegedly gives you better chances, further enticing people to move out of the R zone.