Welcome to Librarium Online!
I have been away from the hobby for alooooong time (because I found beer, girls, job ect..) the last 3 years i've been playing fantasy and am now getting back into 40k (but in pidgeon steps) hence a nice small points game.
5x Rangers 95pts
6x Harlequins + shadowseer + 6x Hkiss 162pts
2x War Walkers + EML x4 140ish pts
Please give me some pointers, is this too hard for a friendly, not hard enough? How should I equip the WW? I will be playing mostly against space marines. (no surprise there).
The reasoning/stratagy behind the list is to pin the enemy with EML and sniper shots then jam the Harlies in their face, and I only chose the models I like the look of (which works for me in WFB.
Presuming you're playing the old combat patrol version with the limitations on armor allowed, you'd probably do better with scatter laser walkers. That would also give you some points to upgrade to pathfinders.
In any case you'll want to rig things like walkers up so you can swap weapons later. Magnets are the best, but in the short term you could use weak glues that you can pull apart.
Anyway rangers might do just fine in combat patrol. However Marines have a habit of passing leadership tests, which would leave the unpinned when the harlies get close. And harlies don't hold up so well to bolter fire.
That said I think harlies can be a good edition to the army so you might as well have some fun with 'em now. The marines could always blow their roll to spot them. Also pathfinders might convence the marines to seek cover, and them might blow a difficult terrain test to step out toward the harlies, who are fleet and ignore terrain.