But for most of us, this is a hobby to spend our time and money. Well-known builders sometimes create instructions for their creations but frequently they don't. This is no surprise: many of the models gathering fame are complicated, fragile or contain special pieces.
An interesting exception is Daniel Siskind, the man behind Brickmania. He built his own business to create and sell sets without any official ties to the LEGO Company. Wars that happened for real are a taboo for LEGO's own designers (for understandable reasons) and this is the gap Brickmania tries to fill: the website offers more than 50, mostly military themed sets starting from World War II until armies in recent history.
The models are built from real LEGO bricks. Since these models are much more special than the ones you can buy in LEGO stores, they are noticeably pricier. For example this Jeep at $35 is one of the cheapest models. It is part of the 'Durabuilder' series, which in my interpretation means that it will not immediately fall apart if kids take it into their hands.
For this the buyer gets an individually packaged set in similar quality, but much more rare, including minifigs and other extras depending on the set.
Tanks form the bulk of the selection: there are German, American and Soviet vehicles as well, for example the T-34 below. This set is a lot more complex than the Jeep: it includes a fully rotating turret, a driver and the tracking mechanism. It contains 724 bricks and at $345 is noticeably pricier.
Besides tanks there are other types of vehicles. The CCKW truck below was widely used by US armed forces during WWII. This is a medium set at $100.
There are a few aircraft too, like this P-51 Mustang. Similarly to the Jeep it is also a part of the Durabuilder line. The number of pieces and price at $100 are similar to the CCKW.
There are probably quite a few of readers at this point who think these sets are way too expensive. On one hand this is understandable since LEGO is not the cheapest toy and these models are clearly above the price level of the official ones.
On the other hand it is also clear that the founder has invested a lot of his time and energy into Brickmania. These models were be designed, instructions printed and individually packaged. They are likely sold in much smaller quantities than official LEGO sets. The most difficult problem is probably to acquire the required bricks in sufficient quantities at a good price. For comparison, buying all bricks for my somewhat smaller sized MiG-15 already cost more than $80 and quite a bit of time.
Overall, I think that if you are into military LEGO sets but would not like to spend time designing and buying parts for your own model, Brickmania is a good alternative.
(bricksngears.com is not affiliated with Brickmania in any way.)