I would like to think i am leaning more to the gentle side my self. My dd1 is about the same age as yours ( i think ) and after DD2 was born and we moved house her behavior went crazy. hitting, allsorts. in the end, after trying every thing i could think of, i had no choice but to get tough, she started hitting kids in the play ground!! also i found i was getting too angry with her and it wasnt constructive.

I took all her toys away, put them in a big cupboard, she watched me do it, i didn't do it in anger, i explained as i was doing it, she cried, but i kept telling her i loved her. then we made a chart, got stickers and taught her the word 'violence' and that she was using violence which was unacceptable when we had violence she got a big sad face on the chart, on a day with no violence she got a sticker, three sticker and she could pick a toy to take out the cupboard, big sad face=loose another toy. i didnt really enjoy the idea of it, but it worked SO well, sure it wouldnt be for every one and might not always work. but i gave me a strong and definite way to express that her behavior wasnt on without getting angry, which is what was happening before.

good luck.