You are free to plow your field whichever way you like, of course. Just step back once in a while and check whether you've done enough plowing last month - or spent all your time upgrading your plowing technology.

In the end you just have to plow, and it doesn't matter all that much how you do it (as long as you use my preferred brand of course). Plowing tech isn't all there is to growing crop and vegetables. There is an awful lot more that you have to understand and plan and take care of, and upgrading your plowing tech won't help you with any of that.