Your ratio is in a normal band. Depending on the county, somewhere around a fifth to a third of new filings involve real property, because a large share of estates are opened for bank accounts, a vehicle, a wrongful death claim, or a guardianship matter that shows up in the same docket. Where people lose records they should have kept is name matching. Deeds carry maiden names, middle initials, trailing trust language, and joint owners who died years apart. If your 48 came from exact-string matching you're probably leaving real property on the table, so spot check twenty misses by hand before you trust the pipeline.
On cadence, both things you were told describe different moments. Mail early to be known, expect the transaction later. Inventory gets filed, the creditor window runs, and the representative usually can't or won't sign until that's underway, which in most states puts the realistic sale window somewhere around month three to month nine. So one touch on a fresh filing does nothing. Six touches across nine months on the same cohort is a shape that matches the timeline.
Run the money on that. 48 mailable at six touches and roughly 65 cents a piece is about 190 dollars per cohort. Once six cohorts overlap you're mailing near 300 pieces a month and spending a couple hundred to five hundred, which is small enough that your real constraint is how you handle the calls.
Two things to build in now. Suppress on recorded deed monthly or you'll be mailing families whose house sold in February, which is how a reputation gets built the wrong way. And some states restrict solicitation of estates during a set period after filing, so have a local attorney confirm what applies before your first drop.