For proper planning, I would do close protection then if you have West Point comm. then withdraw the officer and spam frenchies and taunt and wait until you get twenty and you would probably be wiped out by 19 tps.
During the time when the turtle shells are bouncing, if you go to the shop and wait a little bit it will immediately end your combo at whatever it was at, but not at what the max could be.
Good game, but it becomes rather easy once you get the idea and a good strategy, I think that it shouldn't be as straight forward with bad stuff happening win you are winning and good stuff when losing, also it would be nice to have a bit more of variety of enemies like the V1 and allies too.
An interesting strategy is to get close protection and to get a engineer then spam frenchies but instead of having a bomb come for the huge amount of frenchies cover them with cam nets and you will last to about 50.
When you get a medal that says 1% chance of a free soldier/construction, you can't just mash the buttons and hope, you have to be able to actually afford it for the perk to have a chance at it.