As imho none in this thread consider real hardcore rallying, imho generic street tires will do ok for enthusiastic driving on ice/snow/gravel. If one hunts for results, then it's worth to do more serious modding and rise budget by a LOT.
After all, real rally tires are just like track slicks. They grip better but not for a long. They will last race or two, and that's about it - time to change, to keep grip competitive. Just for "fun" or enthuasistic "rallyish" auto-x normal tires should do. Be it normal street tires for tarmac stages or mud ones for gravel or normal winter tires for ice/snow. And of course it's not just tires. Your own linked thread on rally suspension discussion. "Real" rally coilovers do wonders, they allow all those insane jumps in air, they allow going 200kmh+ on deep holes ridden tarmac or bad gravel road or cut corners over ditch .. but they cost $7-20K set and need to be overhauled every 1K km.
Once one gets into sport seriously, one should have money to back it. My preference is to keep it modest, just for fun, and mods only in way to keep car street legal and daily driveable.
Don't overthink it & keep it simple and of reasonable costs, if it's just for fun.
Yes, with "real stuff" speeds/laptimes will be better, but if it is must if your goal is fun and you have to pay for that from own wallet?