[narwan]

hoplitis said:

Which are ...???

Instead of pressing a button to infiltrate them behind enemy lines as you do in certain other games, here you have to actually infiltrate them through the lines yourselves. Get fast and small vehicles or use helicopters to get them close to the front line and try to infiltrate the line. The very high experience and morale modifiers should help you keep them unspotted, if you move slowly. Unless of course you run straight into the enemy which is always a risk. If you're really a gambling man, keep them in the vehicles or choppers and use speed to get them through the line. Unload them in the rear and start the sneak towards enemy rear area units.
You can use other units in support, either directly as in fire support, or indirectly by drawing off enemy forces to another part of the line, increasing the chance of succesful penetration. Use artillery to either suppress areas where enemy spotters might be hiding (and reduce their chance of seeing your troops) or use them to create smoke screens. You can create corriders that way for helicopters to fly through unhindered.
Lots of options and tricks possible here. But you should remember that commando tactics in addition to regular combat is hard to combine on the more modern battlefield due to the high speed of events.