sleep training

Anastasia
I am literally laughing because I have no idea how to express my feelings to my husband. 
Correct me if I am wrong .. three months is too young to try to sleep train. Our baby will be three months in two days.. my husband hates that we have to hold my baby before she goes to sleep. She wakes up sometimes in the night and I feed her and all is fine. Some nights are harder than others but it's not a trend. She has had a few nights of 6-7 hour stretches. 
During the day I hold my baby. It doesn't really bother me. I know it won't be forever. Tonight my husband was really set on trying to sleep train her. I let it play out until I could here her spit in the back of her throats from her crying. She doesn't really stop unless someone holds her for a minute. It's like she knows that we are wanting her to go to sleep. It makes me want to cry seeing her cry so hard and picking her up and seeing how exausted she looks. I understand down the road sleep training might be a thing but she is not even three months yet. From what I have read 4 months is the mark. 
I don't see the huge issue right now. If it is ligt out she has a hard time going  to sleep. If it is dark and I feed her she is done . 
Am I wrong ?