what if he actually get M3 ?
Assuming he went penals, you will be able to take pretty much the whole map with your early pios. Rush the first penal with 2x pios and you will win, the other 2 pios can be capping. It's easy to take both fuels and a majority of strat points really early, giving you fuel to rush 222. The piospam has a big advantage early early game where they can 1v1 most squads effectively.
Skipping t1 lets you get the 222 out really fast, usually about 30ish seconds after the m3, assuming they went 2x penals then m3. Run around and distract the m3 with your pios to stall time and try to hold map presence, once the 222 comes out you can kill it and take it all back.
The piospam actually works alot better against t1 because of the synergy of pios and the 222. Conspam runs into problems where the cheap pios can't outcap them very well coimpared to expensive penals and at grenades are alot more dangerous than satchels.