Well, what I've read, and per the Mahindra USA website, the backhoe is a factory-only ($6k) option on my tractor. The tractor chassis is different for the backhoe models. There are aftermarket 3-point backhoes, but if the tractor chassis is not made for a backhoe, it apparently will snap the chassis in two. Don't know about other tractor makes/models. I only know what I've read about my eMax 20S. The backhoe is just a, "nice to have," option. The price of the backhoe put it out of my budget, as well.
From what I read on my 20S, the front snowblower also requires a different factory chassis/PTO setup. Living in tropical Minnesota, the front snowblower would've been fantastic, but the price ($4k option), again, pushed it beyond my budget. My sub-compact tractor seems to be more narrow in options, due to its varied chassis configurations, and its limited HP. I would love to have an all-purpose tractor, with more HP, front snowblower, and a backhoe, but that wasn't within my budget. I added bucket skis (Edge Tamer knock-off's), which do a very good job, for less then $200, 1/20th the price of the front snowblower!
Visited the Mahindra USA, build your own, website. The backhoe is only compatible with the FEL and the belly mower, not the front snowblower. The front snowblower is only compatible with the FEL; the belly mower and the backhoe are not available with the front snowblower option.
The sub-compact I bought, fit my budget, as well as my 2nd garage. So far, the eMax 20S has met my needs, surprisingly well. I learned more about it, after purchase, discovering I had stumbled into the best compromise for my needs. It has fulfilled my needs, every month of each year since I bought it. Cheers!