As an Anders player myself I will let you into a little secret. Forge is definitely my nemesis in 1v1 when in the hands of a competent player. He can make Warthogs at the same pace as an Anders player although he can’t get the upgrades as quickly. As well as this, he can also build turrets on his base and get a VD up quicker than Anders. This makes for a very potent combination.
Obviously each map should be played differently but I’ll start with the non-hook maps (Tundra and Release). Forge should aim to make Warthogs up until he has at least got a vehicle depot. Anything less than this means that he is open to Anders’ early Grenadier attack (5 hogs: SP, SP, R, R). You may think that this build order is not do-able but believe me, it is, and has been used to destroy countless numbers of Forge players in the past.
Whilst making the hogs, you also need at least one turret with anti-vehicle. If Anders goes early Grenadier then you should be able to push her off your base as you have an extra hog and an upgraded turret. Once she is off the base then you should be way ahead of her and should have no problems producing tanks to kick her -Yoink-.
If Anders doesn’t go with the early Grenadier then you will still have more money than her. Keep producing the Warthogs but try to go early Canny on your tanks (after having built 2 or 3 of them) and then downtech. This will hurt Anders, even if she has a whole bunch of Gremlins, hogs and tanks. Remember, Anders will always be behind Forge financially in the mid-game which means that it will take longer for her to get to Canny. This is the point where you need to attack her. She will stun your tank(s) but remember that you have also got an army of Warthogs which can kick their -Yoinks!- once the stun has been used and there’s also the Carpet Bomb.
You must also know when to expand and also when to attack her expansion. The Carpet Bomb is excellent at destroying a base with no pads or nearly destroying one which has one pad built. Check her points on the menu screen in order to see when she is clearing the base and then use it when the base has been built. Forge should start taking down his expansion when his first tank comes out.
On maps which have hooks I would say that going barracks first or second is feasible but you really need to watch out for early gunner hogs as they could ruin your day. Because Chasms is such a small map, you need to watch out for Reactor first gunners (I do this all the time against UNSC on this map). The hogs will definitely kick the -Yoink- of any marines that head towards the supply hooks and you will lose the advantage that you hoped to gain by going barracks first or second.
In Blood River you need to go barracks first every time. If Anders goes reactor-first hogs in order to attack your marines then you need to ram her hogs with your gunner-less hogs while at the same time using your marines to throw grenades at them. If Anders doesn’t go early gunner but still decides to ram your marines then do the same as above (it will be easier this time).
In Barrens you need to go Reactor first as any decent Anders player will be doing the same. When your second hog is made, upgrade to gunner but keep your hogs away from hers until they are upgraded, then attack. If she didn’t go for the reactor first gunner hogs then you get to kick her -Yoink- while returning to the middle in order to be healed for free. Just keep picking her hogs off one by one until you outnumber her and have full control of the reactor hooks and bases. If she did go reactor first then you are about even with her and will have a fun game. Remember when going Reactor first, you can always cancel the Reactor once you have started researching gunner in order to get more cash for your next hog.
On Pirth you are bound to lose but it’s always good to try. The main tactic is to attack Anders’ expansion with hogs. Any decent Anders player would lock both bases down in order to build hogs, hogs and hogs. For the first couple of minutes you are in the driver’s seat as you have been able to make hogs from the start. Going reactor first will allow you to attack her base earlier which puts her under more pressure to do something, earlier. The downside of this is that while you are attacking her expansion, her two hogs can collect all of the money around the map. Going reactor second is most people’s usual choice. Keep building hogs and keep attacking her expansion while remembering to build an expansion of your own when you have the money. This is usually the point where Anders opens both of her bases up in order to release all of the hogs that she has been making this whole time. If you are playing against someone decent then this is usually the time to get the hell out of there as she will have ensured that she has more hogs than you. Now you need to defend your expansion while getting a barracks up in order to take your reactor and research Grenadier for your hogs. From this point things can go in any direction. You need to be building hogs, RPG marines and tanks in order to counter all that Anders has to offer. If you get to this point without losing then good job and enjoy the rest of the game.
Hope this helps.