First off I’d like to point out that I have no knowledge of the actual armor values of Namer 30 tank, nor of the merkavas, so everything here is based on common sense. With that out of the way, I’d like to discuss the armor values of those tanks with both gameplay and realism in mind.
Namer 30
The weight of this IFV is known to be around 60 tons, and so is the engine it uses. With that, we can estimate it’s mobility, I believe in game it’s on the lower end of its capabilities, but still somewhat realistic.
But now comes the more important part, the armor.
In game, as it stands now, the namer weights 61 tons, 4 tons less than merkava Mk.4, and has only 1/8 of the merkava’s composite on the sides (Namer 50mm external, Merkava 400mm internal), additionaly it has none of the merkava’s protection on the rear. The weight difference of Namer and Merkava is way smaller than weight difference of Namer’s and Merkava’s turrets, so safe to say the “gained” weight had to be put back into the tank primarily in the form of armor.
However it wasn’t, instead, the armor was also reduced.
As for why it shouldn’t be the case, I’ll touch on both historical and gameplay perspective.
Historical/Realism:
Simple maths, weight difference of namer and merkava is lesser than weight gained from removing the turret. Hence the Namer should have a more armored hull than the Merkava Mk.4, instead the front is simmilar, sides have ~80% less composite, and rear is about 30% less armored.
Gameplay:
We have a 30mm autocannon that cannot flank due to horrible mobility. We also cannot brawl due to bad armor, which is only capable of whitstanding other autocannons, and only to the front. The only thing we can do then is utilise our great gun depression and crewless turret to fire at enemy vehicles from relative safety. However then we face MBT’s from the front, but we cannot destroy them from the front, disable at best (with few exceptions), last hope is the spike missile, but that one, as we all know, is super unreliable and frankly just bad. Other crewless turret IFVs on this BR can flank, capture points and assist the team in many many more ways than just disabling tracks and cannon barrels, while having a simmilar level of protection - close to none against MBTs, the most common opponent.
Solution:
Improve Namer’s armor to the point where, with proper angling and some luck it can whitstand MBT fire, and can also survive 30mm autocannons to the side, giving it an actuall advantage in an IFV vs IFV scenario. OR Improve the mobility by reducing the weight, making it comparable to other IFVs on this BR, allowing it to flank, this however would make it stand out much less and is probably a less historically accurate solution. If neccesary, Namer’s BR can easily be increased, since as it stands now Israel has lineups on 9.3 and 11.0, using 9.3 tanks with the Namer is pointless, hence the Namer is used at 11.0 anyway, and by many even higher, 11.3 or 11.7.
Merkavas
A short note about the merkavas in the end.
It would make sense for the more modern merkavas hulls to be able to take a round from an older MBT, which in the game would be around 10.3-10.0 levels of penetration (400-450mm). Hard to believe that the front plate is barely upgraded from the first Mk.1 variants. While the 9.3 (and 9.7 premium) are good tanks and 11.0 variants can be excused with frequent downtiers, 11.3 and 11.7 Merkavas are simply inferior to other tanks at their respective BRs. They have the second worse armor when it comes to top tier APFSDS (With only the Ariete being worse). Where even tanks considered to be poorly armored such as Leclerc and Type10 still have places on the hull that can survive a hit and their turret cheeks generally are also able to survive a shot. Merkava on the other hand doesn’t have a single spot on the hull that could survive even a 10.0/10.3 round, and only in some places on the upper part of the turret can it bounce top tier rounds. It’s mobility is also just average, so is the firepower, and then on top of all it’s huge and terribly easy to spot and hit.