I’d lean team 1 for this event, based on what you’ve said about your practice with it. Being familiar with your own leads, switches and endgames is a stronger reason to pick a team than hoping the opponent won’t recognise it. A known team still asks them to make the right decisions, and team 2 has a matchup you already feel unsure about.
For team 2, I’d test the weather positioning before changing Pokémon. Keeping Pelipper in reserve gives you a way to replace sun and remove Chlorophyll’s Speed boost when you need it. Don’t treat that as an automatic Venusaur answer, though: you still need to get Pelipper in safely, and Charizard can bring sun back. Work out a lead and a safe rain-reset turn against that pair, then check whether the plan survives them targeting Pelipper instead of Garchomp.
Also decide which Mega you’re bringing in that matchup. Golisopod and Garchomp both hold their stones, but only one can Mega Evolve in a battle, so the other needs to earn its slot in base form. I’d take team 2 only if those practice games give you a repeatable plan you trust. Otherwise, team 1 sounds like the more comfortable choice; surprise alone wouldn’t make me switch.