You have not read my dissertation--------
Disc Harrows come in even pan diameters, ie: 18" -20"-22" etc. Up to 22" pans are almost always offered only notched, also called scalloped. These cut better, compensating for light weight. (Minor issue: Notched pans deform a little easier, wear a little faster.)
The key factor is implement weight bearing on each pan, with forty pounds per pan being minimum effective weight in sandy soils, really for field use rather than food plot use.
For food plots you need fifty to sixty pounds bearing on each pan, because the ground has not previously been broken with a plow, usually, therefore you cannot adjust the gang angles as aggressively and because usually you want to complete soil prep in one pass because of a lack of maneuver room or because of operating on slopes, where you do not want a second pass over disturbed ground.
You get more weight per pan with larger diameter pans (Pi = 3.14), which are also thicker, or by spacing pans at 9" rather than 7", which yields fewer pans per gang. Fewer pans mean less pan "float", better cutting action.
Seven inch and 7-1/2" spaced Disc Harrows are for smoothing furrows created by a moldboard plow in fields. Nine inch pan spacing is for cutting in food plots and fire breaks.
(Monroe Tufline offers heavy Disc Harrows with 9" spacing front, 7" spacing rear, for those who have difficulty with decisions.)
BUY HEAVY.
After seeding the optimum implement to maximize small seed germination and curtail erosion is a Cultipacker.
There are NO TILL Food Plot mixtures based on clover. Being low, less yield than general food plot mixes. I do not have experience in NO TILL category.