Yes like I said its useful at times, "cheat" I have been known to use if I have APCs that are not up to much is deploy them as a second line of defence. If operating tanks becomes untenable probably due to arty pull them out & take up 2nd line positions evacuated by APCs. You have to be aware that if these APCs enter his LOS he will know the entrenchment locations, not done on purpose but have fooled a player into blitzing with arty there empty emplacements before as they engaged
When deploying on the defence taking into account what happens if the player takes over your fortifications should be a factor & making them a pre targeted arty hex is worth considering so can hit him before gets a chance to dig in. Once enters the hex he will be dug in at the start of his next turn. Bit unrealistic for vehicle maybe as will need to position but infantry are just taking over a hole in the ground.
Can use the same thing for your arty giving them a second emplaced zone to move to
Great fun sticking your MGs in his defences & pressing on if he has set next lot up in sight of.