I don't know what is the best solution to solve the problem you are describing.
   I've been using pmake for many years now, and I've seen the broken behavior
   you mention. Most Makefiles do work correcly without -B though [I would say
   close to 95% of the Makefiles that one tries]
   
       make -j 4 obj && make -j 4 depend && make -j 4 all
   
   works like you expect it. 

i've seen a few problems over the years when doing "make target1 target2"
rather than "make target1 && make target2".  without having a fully
informed opinion, to me, what currently happens (minus <see below>) is
the correct behaviour.  if you say

% make -j 4 obj depend

and there are no rules saying that `obj' depends on `depend' (which there
bloody well should _NOT_ be  :-) then it is very reasonable that things
will Get Confused.  this, to me, is pilot error, not tool error.
   
   Maybe the default -j 1 should imply -B?

yes.  i think that by default, `make' should NOT act as a parallel make,
thus, -B should be turned on.

later,

.mrg.