The wings do the same things as EVs, yes. IVs and natures go a long way to any particular Pokemon's success in battles as well. Finally, the Pokemon you're using might just not be good for competitive battles/have the wrong ability/have poor movesets. It'd help us help you if we knew more, but to answer your question, yes, the wings are an extremely long way to EV train. I also know that Join Avenue can help with EV training, but I haven't experimented with it enough, nor do I care enough to do so, to be able to inform you more. I'm sure someone here has, though.