Any engine can work, there are advantages with choosing engines that people build similar games with. I spent ~6mo "adding" core engine features(LoD streaming,

Any engine can work, there are advantages with choosing engines that people build similar games with. I spent ~6mo "adding" core engine features(LoD streaming, etc) to a UE3 open-world title because most of the games on UE3 at the time were very on-rails shooters. That said I agree 100% with building tiny games in an iterative fashion to understand the engine you're using, or taking a very narrow "vertical slice" to help flush out where the technical or game mechanic issues will be. There's a wealth of good engines out there today where you're building on in some cases literally decades worth of development that can accelerate a lot of the work involved in building a game(and there is a lot of work there).