WWII tank crew typically had pistols or revolvers as their personal sidearms. Other weapons were sometimes included as part of the tank's equipment, but not always. For example:

• Early British tanks: nothing. The only sidearms were the crew's revolvers.

• Early US tanks: 1 Thompson M1928A1 SMG and 12 grenades.

• Late US tanks: 5 M3 submachine guns and 12 grenades.

Even in cases such as the first one above, where the tank equipment included no personal weapons, the unit had small arms at the company/squadron level and higher, and could issue them to crews (especially SMGs). Crews could also acquire further weapons and stow them in their tank; captured enemy weapons might be so used.

Generally, there was a trend during the war to provide more SMGs. The US growth from 1 Thompson to 5 M3 SMGs typifies that. The British increased their issue from zero to 1 Thompson to multiple Stens.

Finally, the turret-mounted machine gun was sometimes a typical infantry machine gun and could easily be used removed from the tank. For example, this Matilda is equipped with a Bren:

• https://www.iwm.org.uk/collections/item/object/205222626

WWII photos of tank crew typically only show them with pistols/revolvers. Sometimes, other weapons are visible - as noted above, usually an SMG:

• https://qph.fs.quoracdn.net/main-qimg-9d7447050fc27cbc717aee651e4ee068

but sometimes other weapon are visible:

• https://www.reddit.com/r/TankPorn/comments/b39t3i/sherman_m4a3e8_with_additional_sandbags_armor/

(note the carbine leaning against the turret, next to the gun mantlet).