Implementing an FTL quite simple with templates

[Khatovar]

That sounds like they aren't getting the assist part, which means they aren't responding to the modifiers.

// %1% : master-key
// %2% : slave-key
<Template FTL>
          <Hotkey %1%>     
                    <ApplyTemplate SendLeaderless "%1%" "%2%" "rctrl Divide" wow1 "w2,w3">
                   <ApplyTemplate SendLeaderless "%1%" "%2%" "rctrl ralt" wow2 "w1,w3">
                   <ApplyTemplate SendLeaderless "%1%" "%2%" "ralt Divide" wow3 "w1,w2">

//                <ApplyTemplate SendLeaderless "%1%" "%2%" "rctrl rshift" wow1 "w2,w3">
//                  <ApplyTemplate SendLeaderless "%1%" "%2%" "rctrl ralt" wow2 "w1,w3">
//                  <ApplyTemplate SendLeaderless "%1%" "%2%" "ralt rshift" wow3 "w1,w2">
      
<EndTemplate>

I'm seeing a problem here. Divide isn't a valid modifier, WoW will only consider Divide as a standard key, so you can't use it as a macro condition. The only valid modifiers for WoW macros are ctrl, alt and shift, so you need to use any combination of those. Remove the top 3 ApplyTemplate commands in Template FTL and uncomment the bottom 3 {remove the //}.

// %1% : master-key
// %2% : slave-key
<Template FTL>
          <Hotkey %1%>     
                <ApplyTemplate SendLeaderless "%1%" "%2%" "rctrl rshift" wow1 "w2,w3">
                  <ApplyTemplate SendLeaderless "%1%" "%2%" "rctrl ralt" wow2 "w1,w3">
                  <ApplyTemplate SendLeaderless "%1%" "%2%" "ralt rshift" wow3 "w1,w2">
      
<EndTemplate>

And then make sure your macros are using the listed rctrl/ralt/rshift info in the assist.