The main religious text of Sikhism 'Guru Granth Sahib' mentions Hindus and Muslims many times. Islam considers Azrael as an angel of death. All people will see him while they die. In Sikhism Azrael is also an angel of death but only sinful people will see him while dying.
This is one similarity. Another similarity is the concept of God in Sikhism is similar to Islamic concept of God. (Strict monotheism). Idolatry is also strictly forbidden in both religions. There are also other similarities.
Now there are also similarities between Hindus and Sikhs. Married women in both religions put sindoor / vermilion (one kind of red powder) on forehead. Both religious groups believe in Reincarnation. Both religious groups burn dead bodies.
Guru Nanak says he is not Hindu, he is also not Muslim. Guru Nanak mentions Hindu scriptures and Muslim scripture in his writings many times. He says Allah of Muslim and Ram of Hindu both are acceptable names of God. Guru Nanak was born in a Hindu family but he was not interested in worshiping idols. He also visited Mecca, the holy city of Islam in his lifetime.
I think Sikhism is a combination of Hinduism and Islam. What do you think? How could the hexagrams of the I Ching be viewed as a means of divination? How could they be seen as having personality and wisdom of their own? Note the editorial work of Confucius.
Sahajdharis- conservative and slowgoing, reject militant characteristics. Singhs-