It depends on what you mean by troops, tech, and monitoring.
I do agree, though, that a fence is, BY ITSELF, not an effective strategy. The maginot line proved that.
The French seeing no threat from Belgium didn't build the Maginot line through that sector.
Their thinking, like Perry's, imagined that the opponent is stupid and won't just move down the road to cross where you forgot to build a fence.
In any case, the wall was not contiguous and consisted of a number of ouverages (essentially independent fortresses housing thousands of troops) that had overlapping fields of fire that could destroy just about any invader attempting to come their way.
The "line" was superfluous and only a few of the ouverages had to be taken by combat, and then only much later in the war!
Essentially the Maginot Line worked well. France escaped substantial property damage in the Isle de France as a result ~ which was the purpose. Now the coast? That is another question entirely!