It was planned that, after the B1 Ter had been finalized, the B1 Bis (on the new tanks only, not the ones already made) would have received some of the improvements such as:

- Horizontal aiming of the 75mm
- Welded driver hood (instead of casted)
- Improved Naeder system
- Either the ARL 2 turret (armored at 60mm) or a new deep drawn turret.
- Improved engine
- New cooling system for the Naeder

Plus some others modifications such as a Cotal automatic gearbox and the replacement of the 75mm by either a 105mm (from the 105mm Mle.1928 Mountain gun) or a 135mm (from the 135mm Mle.1932).

But as far as my sources knows, no B1 Bis were modified.

In 1940 with the losses of the Northern France factories there was a lack of turrets (with the APX 1 CE of the S 35 though to be used as replacement) which made that B1 Bis were produced and send to the battle without turret (a 60mm thick plate covering the hole).
As example, the B1 Bis n°505, destroyed the 22 June at Tournon-Saint-Martin, one the 11 B1 Bis of the lieutenant Bibes company:
http://www.chars-francais.net/new/index.php?option=com_content&task=view&id=467
Also note the additional, armored, rear fuel tank.

The 75mm was the 75mm Mle.1935 by the ABS, shortened designation: 75mm SA35.
The 75mm Mle.1929 existed but it was a fortress gun.

The APX 4 turret weighted 2570kg so by removing it a B1 Bis would indeed approach the 28t.

The B1 Ter would have been equipped with an uparmored ARL 2 turret (70mm), which is not a two-men turret but, once again, a one-man turret.
To resume:
- ARL 2 C (40/40/60) – Somua S40
- ARL 2 (at 60mm) – Planned improved B1 Bis
- ARL 2 (at 70mm) – B1 Ter
The B 40, in its initial configuration, would have been equipped with a two man turret armed with either the 47mm Mle.1934 RF or the 47mm SA37 (plus a 105mm hull gun), it was later changed to a single 75mm in a three-men turret.

Second I mentioned the lack of Hull Change. I would quote myself but that seems pointless as you cant read.

Thirdly the more powerful engine you get in game is actually off the Ter.

And I think that the Ter used the same tracks as the Bis but need to check as I have not read up on the B1 for some time.

If this were in the game it might actually make tier 4 more fun to play (since it seems that for the most part the only fun tier 4s that aren’t premiums are tank destroyers)

Problem with the tank in game (Bis version, at least), is its awful gun. It was pretty good IRL, and is complete shit in WoT.

That being said, I found the B1 to be pretty imba when I grinded the french heavy line. The armor made it pretty much invincible against other tier 4s. Mind you, that was two years ago, before the insane power creep that also plagues low tier tanks nowadays.

The hull isn’t the same, the engine isn’t the same, and it doesn’t have the planned two-men turret either.

The only thing it’s got is the 47mm, as I don’t think the Ter version was supposed to receive any gun upgrade. Saddly, while it could pretty much blow up anything the germans had at the time, it’s completely gimped in game.

I wish WG buffed the B1 Bis or made a tier 5 B1 Ter. This tank was probably as impressive (and unreliable) as the KV1 at the time, yet it’s complete shit in game.

The balancing would be hard for it, tier 3 and it’s armour is very strong, better than the Pz2J really and that thing’s a nightmare, yet as the B1 ingame can testify, not much for tier 4 with a poor gun to back it up.

Maybe B2-style tiering? Tier 4 that only sees own-tier?