@herochild: Even before factoring EVs, IVs, etc. into a Pokemon, the first, most important part of a team is to keep their leveling even. If you don't, your team will surely fall apart.
Nonetheless, I'm sure everyone has gone down the same path as you in their beginning. I, too, am guilty of that.
Believe it or not, I've only been a competitive battler in full understanding within the last year. I knew all of the factors, but I didn't begin incorporating them until about early June. I remember my Crystal version and Sapphire versions. I did the same thing as you, with Feraligatr and Swampert, respectively.
Just trust me, keep an even team, and you'll do fine.
for some reason, I never let my Marshtomp evolve.
