You're asking two different questions here. In terms of Tawheed as a theology being an offshoot of Ismaili Islam, it's true, the Ismaili roots of Druzism are very obvious. In terms of our genetic origins and makeup, no one really knows, however genetic testing shows that as a population overall we're the same as the other Levantine populations in Syria and Lebanon AFAIK. The Tanukhids for example were an Arab tribe that migrated from southern Arabia to the Levant in the 2nd century, they were Christianized, then converted to Islam and finally their Emirs of the Chouf mountains converted to Druzism. They were the biggest Arab tribe that joined the Druze call. A big issue with this is that our history wasn't really documented until the 15th-16th century, so no firsthand sources exist about the proto-Druze and the early Druze. Oral traditions differ by agenda, people make a big deal about our fair skin complexion but it's not so different from your average northern Syrian/Lebanese, so God only knows where we really originate from, if I had to bet, I'd just say a mish mash of local Levantine populations.
The question is a bit nuanced. Firstly it is an ethnoreligion, which has ethnic heritage as far back as the time of Jethro, Moshe's (Moses) father in law. Secondly, the Druze which again is ethnic AND religious group---is Abrahamic... It is not Christian or Jewish or Muslim; the ethnoreligion element is similar to Judaism, but one key difference. It is a closed religion. There are no conversions in our out of the tribe (about one million worldwide). They are also not open to giving information about their traditions to outsiders. For western people to have a relatable comparison.. think similar to Amish in the sense of the separation from worldly things as much as possible. Not all are as strict, but that is the essence of things and why the religion is closed. The religion itself only became organized around 1100 current era, I want to say in Egypt under the caliphate at the time. Likely why they are so secretive about their faith as well. While it is not Christian, Jewish or Muslim, it does recognize key elements and figures from other Abrahamic religions. I will say, from what I know of them, they have a belief of reincarnation similar to Judaism, no hell or heaven .... Not in the way Christians believe. In Judaism, we call it Gilgulim Neshama "cycle of the soul". They have similar known traditions to all 3 religions, but what I do also know, is that their most central "prophet" seems to be Jesus, if that helps Christians out with an answer... The closest thing I can give anyway lol. He's seen as a Prophet to them, but a highly, HIGHLY regarded one. It's a layered question with an even more layered answer than I can even give without writing a book. I'm half Arab and I'm also half Mizrahi (Persian) Jewish and religiously Jewish. Ethnoreligions are a tricky thing to explain to people, because it's very much nuanced with many variables. When you're dealing with ethnoreligions it gets very complex, especially when the official religion wasn't cemented until so much later than the others. It doesn't make Druze religion an "offshoot" religion either, which I feel is important to say. I've heard Muslims suggest they're an offshoot of Shia, similar to Alawite, which is not correct. Being in a certain culture, which had certain traditions with regards to treatment of other religions and a history of forced conversions, to suggest that because a culture developed under a theocracy, is a direct part of that culture is a bit reductive. There are many people who are often Spanish, Portuguese, Italian and even Greek you who discover that despite being Christian, their DNA suggests Sephardic Jewish lineage in their profile. Same with Arabs who discover Mizrahi Jewish dna. Forced conversion can cause these surprises later on down the road. I think there are CULTURAL influences, but that their religion is unique and being a closed religion does murky things, but I respect it and the Druze people. I will also say, for my Christian friends. An interesting thing I recently read was that, upon studying the samples from the alleged burial shroud along with the alleged remains of John the Baptist, they were found to have DRUZE mitochondrial DNA, which suggests that, in the time of Jesus, on his mother's side... When the conversion in Judaism was not as strict and when Druze didn't disallow conversion, that at some point, his mother's family had married a member of the Druze tribe. He was still obviously Jewish, a Rabbi, but I thought that was really interesting. What we know is that Druze can be found as far away from the Middle East as Venezuela. So, if you have Hispanic lineage... Not only do you have a 25% chance of having Sephardic Jewish DNA , but also Druze is a possibility. Thought that was a pretty neat facto!