The Naval Infantry didn't start receiving large numbers of SVTs until after 1941. It wasn't until 1942/1943ish that SVTs began being massed in more "elite" units like Guards units, Naval Infantry units, and Mechanized Infantry units. Even then, they typically were not the sole rifle in use, but were used to supplement the firepower of the other soldiers armed with Mosin-Nagants and SMGs.
And SMGs like the PPsH-41 weren't even in use during 1941, only relatively small numbers of the earlier PPD SMGs. The PPsH didn't even begin production until November/December 1941, and then only in very small numbers. They weren't mass produced and distributed until early 1942.
Initially, Naval Infantry units in 1941 were just ad-hoc units thrown together from naval personnel who had little infantry training to meet demands for more manpower, especially in besieged areas like Odessa, Sevastapol, and later Stalingrad in 1942. And they would have been equipped with whatever weaponry was available. It was only after they proved themselves capable and courageous during these battles in 1941/1942 that they began to be viewed as more "elite". So it's possible that Naval Infantry could have been primarily armed with semiauto/automatic weapons towards the end of the war, but certainly not in 1941, and I doubt the Mosin-Nagant ever went fully away within Naval Infantry units.
Those Naval Infantry photos I posted are not from training. The 2nd one and possibly 3rd one are staged propaganda photos, but the 1st is an actual battlefield photo from Stalingrad.
In January 1941, the US Army consisted of only ~243,000 soldiers, and they had ~170,000 Garands.
The M1911 was the sole standard sidearm in 1941. But in 1942, it began being supplemented by the .38 S&W Victory, since M1911 production couldn't keep up with the massive rapid increase in the size of the US military. Even then, there were only about 352,000 S&W revolvers provided to the US military from 1942-1945, versus about 2.6 million M1911s from 1912-1945
Brens were the standard LMG present in every first-line British infantry section (squad) at the start of the war in 1939. However, after the disaster in France in 1940, Brens were in short supply in England, along with most other small arms. The BEF lost nearly 23,000 Bren Guns during the fall of France. So thousands of Lewis guns were brought out of storage, and were briefly put back into somewhat common use alongside the Bren among infantry sections, until Bren production could replace all of the lost material. But by 1941/1942, the Bren gun was back to being the sole section LMG, and the Lewis gun was relegated back to secondary roles.
And as stated above, the Lewis persisted in slightly more common use as an infantry LMG in the outlying areas, like the Middle East, East Africa, Southeast Pacific, etc. But there were still plenty of Brens present, even in those areas.