I wouldn’t make both swaps. I’d keep Leaf Storm on Venusaur for now: removing it leaves your current set without a Grass attack, and Garchomp already gives you Earth Power coverage. Earth Power on Venusaur is legal in M-C, but I’d want a specific matchup it fixes before giving up that immediate Grass damage.
Your screenshot has Weather Ball on Charizard rather than Ancient Power—is the Ancient Power version newer? Solar Beam is a legal option to test on Charizard, but this is a sun/rain team, so watch the weather before committing. If Pelipper comes in and replaces sun before Charizard attacks, Solar Beam needs a charging turn. I wouldn’t trade away coverage just because it looks stronger under perfect sun.
For playing the team, start by choosing a main mode at preview: Charizard + Venusaur for sun pressure, or Pelipper + Archaludon for rain. You can bring both weather setters, but have a reason for the weather switch instead of treating them as interchangeable. I’d test the existing Venusaur set first and change only Charizard’s coverage slot, so you can tell which change actually helps.