MuadDib,
You are correct that some TBM's were used at Midway.
The main US torpedo bombers at Midway were not TBM Avengers, they were TBD Devastators. The TBD is an entiely different beast and completely outclassed by the SBD and its own replacement, the TBM.
TBD Devastator:
The TBM was just entering service when Midway happened, and it served through the rest of the war and into 1952. So yes, that is what I menat by mid-late war.
The early war stuff was in service before the US was directly involved in hostilities, things like the SBD, TBD, F4F, P-40E, B-17D.
On another note, its kind of too bad that we're getting the D3A1 istead of the D3A2. While the bombload of both versions is fully outclassed by the SBD's bombload, the D3A2 at least has a performance edge on the SBD. The D3A1 has the same top speed (241mph), is vastly more fragile, has a smaller bombload (250kg + 30kg under each wing) and weaker guns. The D3A2 was produced in greater numbers than was the D3A1, had a slightly greater payload (250kg + 60kg under each wing) and was significantly faster (281mph).
With the D3A1 the Japanese will be working from a even greater disadvantage than the would with the D3A2. The SBD-5 is vastly superior in all ways save turning radius.