if dragons are the same size as horses, they can kick with their back legs and claw with their front legs, or rear up on their hind legs and hit with their front legs like horses or bears do. Even elephants can rear up on their hind legs, so any smaller four-legged animal should be able to to it, freeing their front legs to attack.
https://www.google.com/search?q=elephant+standing+on+hind+legs&newwindow=1&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjK7e-kguzjAhWH11kKHVS3DnoQ_AUIESgB&biw=1924&bih=9201
So if your dragons have front legs as strong as tiger front legs, or horse front legs, or bear front legs, or even human front legs, they will have some use in fighting.
In fact every body part of your dragons, like every body part of every real animal, will have some use in a fight.
Your dragons seem to have many times the mass of Asian water monitor lizards (Varanus salvator) which are said to use their tails to fight as well as teeth and claws https://en.wikipedia.org/wiki/Asian_water_monitor2, and even several times the mass of Komodo dragons that:
have been observed knocking down large pigs and deer with their strong tails.
https://en.wikipedia.org/wiki/Komodo_dragon3
Since your dragons will be more massive than any birds, their wings should be more massive than any birds.
Mute swans can be very aggressive in defence of their nests and are highly protective of their mate and offspring. Most defensive attacks from a mute swan begin with a loud hiss and, if this is not sufficient to drive off the predator, are followed by a physical attack. Swans attack by smashing at their enemy with bony spurs in the wings, accompanied by biting with their large bill, while smaller waterbirds such as ducks are normally grabbed with the swan's bill and dragged or thrown clear of the swan and its offspring. The wings of the swan are very powerful, though not strong enough to break an adult man's leg, as said anecdotally.[29] Large waterfowl, such as Canada geese, (more likely out of competition than in response to potential predation) may be aggressively driven off, and mute swans regularly attack people who enter their territory.[30].
https://en.wikipedia.org/wiki/Mute_swan4
Since your dragons, small though they are, would have many times the mass of swans, their wings should have many times the mass of swan wings, and thus should probably be able to break bones with strong wing swings.
One possible tactic would be to knock down an animal with a blow from a wing and then bite or claw the throat to kill it. Another tactic might be to strike a smashing blow with the wing at the opponent's neck, to break the neck and kill it instantly.
If your dragons were many times larger than you indicate, as large as Smaug the Golden, then one could truthfully boast:
My armor is like tenfold shields, my teeth are swords, my claws spears, the shock of my tail a thunderbolt, my wings a hurricane, and my breath death!"
http://lotrproject.com/quotes/character/smaug 5
In the movie Rodan (1956) the giant "terror dactyls" made hurricane force winds with their wings to blow away buildings.
Since your dragons are so tiny compared to Smaug or Rodan they should't be able to blow away human sized opponents, but if they fight in a sandy desert or a swamp they might use the tactic of blowing dust, sand, or water into their opponents faces to blind them while fighting.
You write:
It shouldn't leave the dragon wide open and most definietly not expose the dragon's tummy (their weakpoint)
And I ask why should a dragon's tummy be their weak point? Why can't a dragon have a rib cage which extends down to their abdomen? Why can't a dragon, like a turtle, have a shell on their abdomen?
And even if your dragons have unarmored bellies, will those weak spots be exposed to much danger when one them rears up on its hind legs and tail and stretches out its front limbs and claws and coils back its neck, ready to strike with its jaws, and gets its wings ready to wack at the opponent?
