It depends on what you mean by 'balance.' If you mean balance as in half the team acts offensively/the other defensively (I doubt that's what you're going for, judging by the fact that your team is using pretty much all attacking moves, which is perfect for ingame team imo), then no not really because Zekrom is more of an offensive Pokemon stacked upon more offense.
If you mean by TYPE, as in they cover each other's weaknesses, then not so much either. This link will take you to a site where you can enter six Pokemon and see how well they handle against different types. Your team in particular (if you went for Zekrom), would be weak to Dark, Ghost, and Rock. You have weaknesses to them and resistances to handle them. You can try out different Pokemon in Zekrom (or another Pokemon's position), to try and get the perfect type synergy you want. We also have a type coverage calculator, where you can enter in what you want to resist, and it will find the perfect Pokemon for you in seconds.
If you want general, all around BA Pokemon, you're pretty solid in that regard,,,
And welcome to the site, click the blue links to take you to the tools I was referring to above.
