I think that used to be true on older cars, but with modern passenger cars emissions/fuel use for start up is about the same as 10s of idle. No clue if that's true for these big diesel vehicles tho.
Idling diesel is supposed to be very bad but long haul trucks are better at it because they need to keep refrigeration running. Either way, something like 2 minutes of idle is almost universally worse.
You keep saying this like it's a gotcha when even the barest level of research shows that it's still better.
Emissions from battery production can vary wildly depending on the process used and manufacturing energy grid. According to this study, manufacturing an 80kWh battery will release between 2400kg and 16,000kg of CO2. A commercial lawnmower will have a ~20kWh battery, so in a lifetime with two batteries we'll guess about 1200-8000kg CO2.
EPA says the average gas mower produces 88lbs of CO2 per hour of use. Over a 2000 hour commercial lifespan that's 80,000kg of CO2. And that's putting aside all the other pollutants and secondary emissions from maintaining a combustion engine.
Do a little research before you start your rants next time.