No need to split the string-to-be-searched-for up into first character/rest of the characters if the capture group is wrapped in a look-ahead.

>perl -wMstrict -le
"my $string  = 'aBrabRabrAbra';
 my $pattern = qr{ brabra }xmsi;
 my $count =()= $string =~ m{ (?= ($pattern)) }xmsg;
 print $count;
 my @matches = $string =~ m{ (?= ($pattern)) }xmsg;
 print qq{@matches};
"
3
BrabRa bRabrA brAbra
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