I see there's a ruling on this matter at
https://bg.battletech.com/forums/index.php?topic=3432.0However, the tables in Total Warfare are still ambiguously worded. The sentence is: "Attacks by non-infantry weapons against mechanized
infantry double the number of troopers eliminated; round all fractions up."
It's the ONLY reference to rounding for non-infantry weapon damage, and the semicolon implies that the rounding only applies to mechanized infantry, not infantry in general. Now, I know that makes little sense, because doubling a whole number will never result in a fraction, but the semicolon is still an odd choice for the footnote.
Of additional interest is that in the first printing of TW, on pg 29, the small record sheet has "Round all fractions up" as a separate footnote, making the process perfectly clear (if inconsistently presented, since the pg 216 table has the semicolon). However, that separate footnote was removed in later printings.
Could errata be published, reinstating the separate footnote, to confirm that the rounding up of fractions applies to conventional infantry troopers in general?