I recommend making a full team of six for each of you, then you can talk and strategize based off of the opponents pokemon and your pokemon. I will constructively criticize as best as I can. I will rate them based on the groupings you did and list a main counter.
Charizard and togekiss: Tailwind is an ok start for you, but charizard? It doesn't have the greatest defenses and in doubles it can be knocked out easily. I assume you use swords dance to start. They work well in sync, but I've found two counters. Azumarill and stealth rocks. Charizard can't really even hit that blue bunny while it just wreaks. Stealth rocks hits charizard and togekiss hard, so watch out. Otherwise, nice!
Sableye and venusaur: Replace double team for foul play. It uses the opponents attack instead of yours. Venusaur looks real good. A good counter to the pair is klefki and mawile. They have perfect type coverage against you, klefki and mawile can't really be hit because of typing and sableyes foul play. You can cover azumarill with this pair, but you don't really have a shot against these guys. Otherwise, great!
Jirachi and gastrodon: They work really well in sync. Jirachi is one of the only pokemon on the team that can EASILY take down fairy types. The only type really stopping you now is ghost. So... what ghost type? Aegislash. You may be able to hit it with earth power and fire punch, but it can tank well. Also, with the dozens of strategys with aegislash, I think it's best to have as many pokemon as possible when facing, then pray for mercy. You can cover it, it's just a little difficult. Other than that, they work really well in sync!
Overall team: Major fairy weakness, which is being a lot more used. You do cover a lot, just the bunnies and car keys. You can cover them near the end of your team, but then ghost types. Honestly, this team is pretty good and hope you can counter the counters. Hope I helped!
P.S. Both of you should use a team of six. Throw in fairy counters.
