So to mention, it remains unclear what is the exact armour protection of Merkava, at least when it comes to standard efficiency against SABOT. Anti-HEAT is pretty well covered in SPBMT, indeed Merkava can be frontally killed only from the Kornet at that point.
Here is an interesting thread covering the expected efficiency. There are solid arguments stating that in fact Merkava is MUCH LESS effective against tank vs. tank combat that one may predict.
Also, there is a formidable note: this is currently the cheapest MBT of all of its class. It could mean some cuts.
http://www.steelbeasts.com/topic/101...ion-estimates/