New hoplite book

[PMBardunias]

Polybius uses epallelon three times in his extant histories outside of 2.69.9 (2.66.9 ; 11.11.7 ; 12.18.5). In all those instances the word is clearly used to describe something (phalaxes or troops of horse) close behind one another.

There's no shame in being led astray by translation, I know for a fact that we have all done it:

?????-???? , ??, also ?, ?? D.C.74.10,al.:—
A. [select] one close after another, in close order, ??????, ??????, Plb.2.69.9, 11.11.7; “????? ???? ?? ?.” J.AJ3.6.6; “??????? ????? ?.” D.C.74.10; ?????????, ??????, ???., Ph.2.288,175, al.; continuous, ??? Hdn.2.7.6; “???????” IG7.2712.54 (Acraephia); “?. ??????” given in quick succession, Alciphr.3.6.
b. [select] Gramm., ?? ?. ??? ??? ??????? succession, sequence of two nominatives, A.D.Synt.179.13,al.
II. [select] ?????????? ?????? by one another's hands (Hermann for ??? ???-), S.Ant.57.
2. [select] “?????? ?.” mortised into one another, Longin.41.3.
III. [select] Adv. -??? again and again, “??? ???? ??? ?????” Dsc.1.115.5; Rhet., ?. ???? ?????????? repeat (e.g. ?????? ??????), Alex.Fig.2.2.
2. [select] “?. ????? ?? ?????????” lean against one another, Ath.10.456e.
3. [select] in alternate succession, Ph.1.397.

Here is I assume what you latched onto:
“?????? ?.” mortised into one another, Longin.41.3. The problem is that ?????? is a bolt or nail, thus either two things are being bolted together or there are a succession of bolts holding something together. In any case where the concept of "mortised" and interlaced came from I have no idea, two things are simply butting against eachother or alternating.