As you probably weren't thinking when you made this topic, there are way more types of pures than just a f2p str pure with 40 att and 70 str. Here, i'll map out all the pures with defense that are successful:
Range tanks: pretty much owning everyone out there, even gsers. They tend to have 90+ range, 70+ defence, and 94 mage for veng.
Zerker pures: pretty much a str pure with 45 defense, they usually have 90+ str and sometimes have godswords.
Barrow pures: a very good account imo, it can do anything a main can do since it has 75 att 90+ str 75 defense, with some range and mage in there for hp.
Initiate and Prosylyte pures: Uses initiate or proselyte as armor, usually has 52 prayer like a zerker and maintains high str+att while keeping defense below 30, occasionally they use godswords, although most stick to whips.
White/Black pures: as close to a stereotypical pure as you can get, has 10 defense for black and usually in members' cases, white armor. They tend to have 99 mage range str hp and 60 att, although they also use godswords.
Obby tanks: 70+ def tanks with 1-20 att and 90+ str. One of the most hard to train pures, but since they use obby mauls they can hit in the high 40's with their maul and in the low 30's with their slayer staff.
As you can see, these pures are very formidable and
TOTALLY OWN 1 def pures, with range tanks and barrow pures being the ones owning mains easily every day.