To begin with, let me establish what I use each mech for:
Chopper – PvP (and usually 2v2 PvP at that)
Bomber – Survival
Tanks are tough, so to kill them on the ground, just strafe around them.
Transforming from ground to air can have a slight delay.
If the tank doesn’t hit you during the delay, there is a time frame where it can shoot you while you are in the air.
Following that, don’t transform at the last minute and try not to transform when the tank is aiming at you.
Being in air form is usually safer than ground.
Don’t push out too far, or you will die quickly.
Rushes happen occasionally, so to counter them, just survive them. It is most likely that the spam of tanks removed all of their funding, so there shouldn’t be any or many defenses at their base.
T99s are bad in PvP. One or two Aegis could let you solo one.
Place your Aegis in forward positions.
Artillery can change the tide of a battle.
Missile ability automatically targets and prioritizes enemy mechs in either form.
Only ground launched missiles target regular enemy units.
HAATs are much better than Seekers, but they cost much more.
An offensive defense is a strategy I prefer. It allows me to gradually move up into the enemy’s base.
Gatties placed in high traffic infantry areas are great for stopping the enemy from getting new outposts.
Reminder that I usually only play in 2v2, so you may need to be more spread in 1v1.
Robot form is melee only, aside from Mantis Strike.
Mantis Strike seems to be a waste of money to me.
Melee slaughters infantry.
Melee doesn’t hit buildings.
Bombs (ability) work well against crowds, especially when they are trapped in stasis mines.
Don’t use so many bombs that you run out of energy for return trip.
You can easily beat most survival maps with a combination of stasis mines, T99s, any kind of artillery, and your bombs ability.
Reminder that I only play bomber on survival, so PvP may be completely different.
Hope that helped you out in some way!