In Southern Europe “Trident,” the tenth level in the Axis campaign, you return once again to some familiar ground. Unlike the previous time you played on this map, things have gotten particularly more snowed over. But more importantly, the Allied counterattack extra path is open from the get go. There are 40 waves of ground units to face in this level, with aircraft arriving on wave 19.
Turret placement should focus on two major fire-bases, one to the north and the south along the red/orange and green/yellow converged paths to maximize effectiveness. One or two turrets placed by the yellow/orange split may be worthwhile off the bat, but will lose effectiveness later on. The central high-ground is perfect for a Cannon ton the left most square, an X-Weapon next to that and some Anti-Air to stop the enemy aircraft.
The run up to wave 10 should focus on getting your first handful of turrets along the red/orange and yellow/green paths with one positioned right as bot merge before the base. In the picture to thre right there is a turret located on the yellow/orange split, however this will be sold later.
Progressing to wave 20, you should focus on finishing all upgrades to the Machine Guns, and then stick one Inferno turret on the convergence points of both yellow/green and orange/red to assist your other weaponry. Cannons placed on the far left square of the high ground and close to the base will have the ability to cover all paths to some extent, so try to get some level 1s up around these points. One AA turret will be needed, placed preferably 2 squares to the right of the high ground Cannon before wave 19. This space in-between will be lefgt for an X-Weapon later.
Towards wave 30 you want to build that X-Weapon on the high ground in the spot mentioned earlier while working towards a second AA turret next to it. Beyond that, its best to have 7 total Cannons at their second level, the one on high ground and 3 on each north and south side fire-base, close to your main base.
The final stretch to wave 40 should involve getting two fully upgraded and boosted X-Weapons, with the second placed in a spot next to the Cannons mentioned previously, close to your main base so that it can hit all incoming paths as well. Fully upgraded Inferno turrets will be a worthwhile investment, but still just the two placed early on.