Sorry to say it, but that image is broken I dont see what you mean.
The Type 2 is a ten-meter diameter dome turret, with a seven-meter diameter, five meter tall (iirc) well*. It carries a pair of 80 centimeter disruptor cannons.
Basically: it's a turret that wouldn't look out of place on an early Dreadnought era wet-navy
battleship.
The big Type 4cs have a bore you could comfortablely
stand in if you aren't especially tall, they're 1.2
meter bores. The lesser medium and small sizes are "only" 60 and 30 centimeter guns, respectively. These are not at all small weapons systems.
Of course, they're still technically smaller than particle beam weapons, since they don't require a great big ring of very powerful electromagnets devoted to making ions go really, really fast, but semantics.
*The part that goes down into the hull.
Edit: also, the Type Two got hurt a little by not having any of the big synergies that stuff like the Type Three and four did, or even the type one for that matter, so ended up in a sort of awkward place where it's only a little above average for your tech level, whilst the
rest of your weapons ended up well above average to "literally almost as powerful as your current technology allows", so it looks kinda bad in comparison.
(The Type Three is ridiculous. You are almost matching the race that has specific techs that make their beams more powerful and have invested into having powerful beam weapons for pure power. Theirs are still much more efficient of course, a few centuries of head start and all, but the fact you managed to even get in the same
zip code is an impressive achievment.)